253239021 has 64 divisors (see below), whose sum is σ = 457228800. Its totient is φ = 135226368.

The previous prime is 253239013. The next prime is 253239043. The reversal of 253239021 is 120932352.

253239021 is a `hidden beast` number, since 253 + 2 + 390 + 21 = 666.

It is not a de Polignac number, because 253239021 - 2³ = 253239013 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253239221) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 864151 + ... + 864443.

It is an arithmetic number, because the mean of its divisors is an integer number (7144200).

Almost surely, 2^253239021 is an apocalyptic number.

253239021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

253239021 is a deficient number, since it is larger than the sum of its proper divisors (203989779).

253239021 is a wasteful number, since it uses less digits than its factorization.

253239021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595 (or 589 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 253239021 is about 15913.4855075813. The cubic root of 253239021 is about 632.6694664821.

The spelling of 253239021 in words is "two hundred fifty-three million, two hundred thirty-nine thousand, twenty-one".