20868555 has 32 divisors (see below), whose sum is σ = 36115200. Its totient is φ = 10253952.

The previous prime is 20868539. The next prime is 20868559. The reversal of 20868555 is 55586802.

It is not a de Polignac number, because 20868555 - 2⁴ = 20868539 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20868559) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9556 + ... + 11534.

It is an arithmetic number, because the mean of its divisors is an integer number (1128600).

Almost surely, 2^20868555 is an apocalyptic number.

20868555 is a deficient number, since it is larger than the sum of its proper divisors (15246645).

20868555 is a wasteful number, since it uses less digits than its factorization.

20868555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2043.

The product of its (nonzero) digits is 96000, while the sum is 39.

The square root of 20868555 is about 4568.2113567566. The cubic root of 20868555 is about 275.3155826109.

The spelling of 20868555 in words is "twenty million, eight hundred sixty-eight thousand, five hundred fifty-five".