253431821 has 2 divisors, whose sum is σ = 253431822. Its totient is φ = 253431820.

The previous prime is 253431817. The next prime is 253431853. The reversal of 253431821 is 128134352.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 194295721 + 59136100 = 13939^2 + 7690^2 .

It is a cyclic number.

It is not a de Polignac number, because 253431821 - 2² = 253431817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (253431811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126715910 + 126715911.

It is an arithmetic number, because the mean of its divisors is an integer number (126715911).

Almost surely, 2^253431821 is an apocalyptic number.

It is an amenable number.

253431821 is a deficient number, since it is larger than the sum of its proper divisors (1).

253431821 is an equidigital number, since it uses as much as digits as its factorization.

253431821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 29.

The square root of 253431821 is about 15919.5421102493. The cubic root of 253431821 is about 632.8299837807.

The spelling of 253431821 in words is "two hundred fifty-three million, four hundred thirty-one thousand, eight hundred twenty-one".