20702720 has 40 divisors (see below), whose sum is σ = 49644144. Its totient is φ = 8280064.

The previous prime is 20702713. The next prime is 20702741. The reversal of 20702720 is 2720702.

It is a tau number, because it is divible by the number of its divisors (40).

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

It is a junction number, because it is equal to n+sod(n) for n = 20702692 and 20702701.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1484 + ... + 6603.

Almost surely, 2^20702720 is an apocalyptic number.

20702720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20702720 is an abundant number, since it is smaller than the sum of its proper divisors (28941424).

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

20702720 is an frugal number, since it uses more digits than its factorization.

20702720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8110 (or 8094 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 20.

The square root of 20702720 is about 4550.0241757599. The cubic root of 20702720 is about 274.5843638578.

The spelling of 20702720 in words is "twenty million, seven hundred two thousand, seven hundred twenty".