253642421 has 2 divisors, whose sum is σ = 253642422. Its totient is φ = 253642420.

The previous prime is 253642391. The next prime is 253642469. The reversal of 253642421 is 124246352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130188100 + 123454321 = 11410^2 + 11111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-253642421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (253642621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126821210 + 126821211.

It is an arithmetic number, because the mean of its divisors is an integer number (126821211).

Almost surely, 2^253642421 is an apocalyptic number.

It is an amenable number.

253642421 is a deficient number, since it is larger than the sum of its proper divisors (1).

253642421 is an equidigital number, since it uses as much as digits as its factorization.

253642421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 29.

The square root of 253642421 is about 15926.1552485212. The cubic root of 253642421 is about 633.0052276188.

Adding to 253642421 its reverse (124246352), we get a palindrome (377888773).

The spelling of 253642421 in words is "two hundred fifty-three million, six hundred forty-two thousand, four hundred twenty-one".