253520721 has 12 divisors (see below), whose sum is σ = 366741648. Its totient is φ = 168762264.

The previous prime is 253520713. The next prime is 253520723. The reversal of 253520721 is 127025352.

It is not a de Polignac number, because 253520721 - 2³ = 253520713 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (253520723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14475 + ... + 26768.

It is an arithmetic number, because the mean of its divisors is an integer number (30561804).

Almost surely, 2^253520721 is an apocalyptic number.

It is an amenable number.

253520721 is a deficient number, since it is larger than the sum of its proper divisors (113220927).

253520721 is a wasteful number, since it uses less digits than its factorization.

253520721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41932 (or 41929 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 253520721 is about 15922.3340311652. The cubic root of 253520721 is about 632.9039708178.

The spelling of 253520721 in words is "two hundred fifty-three million, five hundred twenty thousand, seven hundred twenty-one".