20564220 has 48 divisors (see below), whose sum is σ = 60969888. Its totient is φ = 5160960.

The previous prime is 20564209. The next prime is 20564279. The reversal of 20564220 is 2246502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9061 + ... + 11100.

It is an arithmetic number, because the mean of its divisors is an integer number (1270206).

Almost surely, 2^20564220 is an apocalyptic number.

20564220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20564220 is an abundant number, since it is smaller than the sum of its proper divisors (40405668).

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

20564220 is a wasteful number, since it uses less digits than its factorization.

20564220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20190 (or 20188 counting only the distinct ones).

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

The square root of 20564220 is about 4534.7789361776. The cubic root of 20564220 is about 273.9706754629.

The spelling of 20564220 in words is "twenty million, five hundred sixty-four thousand, two hundred twenty".