20915545 has 32 divisors (see below), whose sum is σ = 30468096. Its totient is φ = 13478400.

The previous prime is 20915507. The next prime is 20915563. The reversal of 20915545 is 54551902.

It is not a de Polignac number, because 20915545 - 2⁷ = 20915417 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39885 + ... + 40405.

It is an arithmetic number, because the mean of its divisors is an integer number (952128).

Almost surely, 2^20915545 is an apocalyptic number.

It is an amenable number.

20915545 is a deficient number, since it is larger than the sum of its proper divisors (9552551).

20915545 is a wasteful number, since it uses less digits than its factorization.

20915545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 20915545 is about 4573.3516156097. The cubic root of 20915545 is about 275.5220716109.

The spelling of 20915545 in words is "twenty million, nine hundred fifteen thousand, five hundred forty-five".