20646774040 has 64 divisors (see below), whose sum is σ = 50517367200. Its totient is φ = 7562815488.

The previous prime is 20646774017. The next prime is 20646774041. The reversal of 20646774040 is 4047764602.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 20646773984 and 20646774002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20646774041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 385150 + ... + 435469.

Almost surely, 2^20646774040 is an apocalyptic number.

20646774040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20646774040 is an abundant number, since it is smaller than the sum of its proper divisors (29870593160).

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

20646774040 is a wasteful number, since it uses less digits than its factorization.

20646774040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820684 (or 820680 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 40.

The spelling of 20646774040 in words is "twenty billion, six hundred forty-six million, seven hundred seventy-four thousand, forty".