253475721 has 6 divisors (see below), whose sum is σ = 366131610. Its totient is φ = 168983808.

The previous prime is 253475707. The next prime is 253475723. The reversal of 253475721 is 127574352.

It can be written as a sum of positive squares in only one way, i.e., 251571321 + 1904400 = 15861^2 + 1380^2 .

It is not a de Polignac number, because 253475721 - 2¹¹ = 253473673 is a prime.

It is a super-2 number, since 2×253475721² = 128499882272939682, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (253475723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14081976 + ... + 14081993.

It is an arithmetic number, because the mean of its divisors is an integer number (61021935).

Almost surely, 2^253475721 is an apocalyptic number.

It is an amenable number.

253475721 is a deficient number, since it is larger than the sum of its proper divisors (112655889).

253475721 is a wasteful number, since it uses less digits than its factorization.

253475721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28163975 (or 28163972 counting only the distinct ones).

The product of its digits is 58800, while the sum is 36.

The square root of 253475721 is about 15920.9208590458. The cubic root of 253475721 is about 632.8665217238.

The spelling of 253475721 in words is "two hundred fifty-three million, four hundred seventy-five thousand, seven hundred twenty-one".