205420864 has 28 divisors (see below), whose sum is σ = 444691008. Its totient is φ = 93372800.

The previous prime is 205420807. The next prime is 205420903. The reversal of 205420864 is 468024502.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145192 + ... + 146599.

Almost surely, 2^205420864 is an apocalyptic number.

It is an amenable number.

205420864 is an abundant number, since it is smaller than the sum of its proper divisors (239270144).

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

205420864 is a wasteful number, since it uses less digits than its factorization.

205420864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291814 (or 291804 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 31.

The square root of 205420864 is about 14332.5107360853. The cubic root of 205420864 is about 590.0400853738.

The spelling of 205420864 in words is "two hundred five million, four hundred twenty thousand, eight hundred sixty-four".