20564040 has 64 divisors (see below), whose sum is σ = 70508160. Its totient is φ = 4700160.

The previous prime is 20564039. The next prime is 20564041. The reversal of 20564040 is 4046502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20564039) and next prime (20564041).

It is a super-2 number, since 2×20564040² = 845759482243200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20563998 and 20564016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20564041) 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, 11401 + ... + 13080.

It is an arithmetic number, because the mean of its divisors is an integer number (1101690).

Almost surely, 2^20564040 is an apocalyptic number.

20564040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20564040 is an abundant number, since it is smaller than the sum of its proper divisors (49944120).

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

20564040 is a wasteful number, since it uses less digits than its factorization.

20564040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24502 (or 24498 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20564040 is about 4534.7590895217. The cubic root of 20564040 is about 273.9698760993.

The spelling of 20564040 in words is "twenty million, five hundred sixty-four thousand, forty".