20646040 has 16 divisors (see below), whose sum is σ = 46453680. Its totient is φ = 8258400.

The previous prime is 20646029. The next prime is 20646049. The reversal of 20646040 is 4064602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20646049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 258036 + ... + 258115.

It is an arithmetic number, because the mean of its divisors is an integer number (2903355).

Almost surely, 2^20646040 is an apocalyptic number.

20646040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20646040 is an abundant number, since it is smaller than the sum of its proper divisors (25807640).

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

20646040 is a wasteful number, since it uses less digits than its factorization.

20646040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516162 (or 516158 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 20646040 is about 4543.7913684499. The cubic root of 20646040 is about 274.3335487217. Note that the first 3 decimals are identical.

The spelling of 20646040 in words is "twenty million, six hundred forty-six thousand, forty".