20797785 has 24 divisors (see below), whose sum is σ = 37294920. Its totient is φ = 10708992.

The previous prime is 20797771. The next prime is 20797789. The reversal of 20797785 is 58779702.

It can be written as a sum of positive squares in 4 ways, for example, as 3732624 + 17065161 = 1932^2 + 4131^2 .

It is not a de Polignac number, because 20797785 - 2⁴ = 20797769 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20797785.

It is not an unprimeable number, because it can be changed into a prime (20797789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6664 + ... + 9273.

It is an arithmetic number, because the mean of its divisors is an integer number (1553955).

Almost surely, 2^20797785 is an apocalyptic number.

It is an amenable number.

20797785 is a deficient number, since it is larger than the sum of its proper divisors (16497135).

20797785 is a wasteful number, since it uses less digits than its factorization.

20797785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15977 (or 15974 counting only the distinct ones).

The product of its (nonzero) digits is 246960, while the sum is 45.

The square root of 20797785 is about 4560.4588584922. The cubic root of 20797785 is about 275.0040109608.

The spelling of 20797785 in words is "twenty million, seven hundred ninety-seven thousand, seven hundred eighty-five".