253721664 has 84 divisors (see below), whose sum is σ = 831153024. Its totient is φ = 72490752.

The previous prime is 253721659. The next prime is 253721681. The reversal of 253721664 is 466127352.

It is a tau number, because it is divible by the number of its divisors (84).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27432 + ... + 35495.

Almost surely, 2^253721664 is an apocalyptic number.

253721664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

253721664 is an abundant number, since it is smaller than the sum of its proper divisors (577431360).

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

253721664 is a wasteful number, since it uses less digits than its factorization.

253721664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62952 (or 62939 counting only the distinct ones).

The product of its digits is 60480, while the sum is 36.

The square root of 253721664 is about 15928.6428800447. The cubic root of 253721664 is about 633.0711419484.

The spelling of 253721664 in words is "two hundred fifty-three million, seven hundred twenty-one thousand, six hundred sixty-four".