42400640 has 64 divisors (see below), whose sum is σ = 102558960. Its totient is φ = 16760832.

The previous prime is 42400619. The next prime is 42400679. The reversal of 42400640 is 4600424.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61739 + ... + 62421.

Almost surely, 2^42400640 is an apocalyptic number.

42400640 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 42400640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51279480).

42400640 is an abundant number, since it is smaller than the sum of its proper divisors (60158320).

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

42400640 is an equidigital number, since it uses as much as digits as its factorization.

42400640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799 (or 787 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 42400640 is about 6511.5773818638. The cubic root of 42400640 is about 348.7044347231.

The spelling of 42400640 in words is "forty-two million, four hundred thousand, six hundred forty".