42720 has 48 divisors (see below), whose sum is σ = 136080. Its totient is φ = 11264.

The previous prime is 42719. The next prime is 42727. The reversal of 42720 is 2724.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 42720.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 42720.

It is not an unprimeable number, because it can be changed into a prime (42727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 436 + ... + 524.

It is an arithmetic number, because the mean of its divisors is an integer number (2835).

2⁴²⁷²⁰ is an apocalyptic number.

42720 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68040).

42720 is an abundant number, since it is smaller than the sum of its proper divisors (93360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42720 is a wasteful number, since it uses less digits than its factorization.

42720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 15.

The square root of 42720 is about 206.6881709242. The cubic root of 42720 is about 34.9577722015.

The spelling of 42720 in words is "forty-two thousand, seven hundred twenty", and thus it is an iban number.