20091564 has 30 divisors (see below), whose sum is σ = 52524164. Its totient is φ = 6697080.

The previous prime is 20091559. The next prime is 20091587. The reversal of 20091564 is 46519002.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 30682 + ... + 31329.

Almost surely, 2^20091564 is an apocalyptic number.

It is an amenable number.

20091564 is an abundant number, since it is smaller than the sum of its proper divisors (32432600).

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

20091564 is a wasteful number, since it uses less digits than its factorization.

20091564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62027 (or 62016 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20091564 is about 4482.3614312101. The cubic root of 20091564 is about 271.8553693317.

The spelling of 20091564 in words is "twenty million, ninety-one thousand, five hundred sixty-four".