257152421 has 4 divisors (see below), whose sum is σ = 272279052. Its totient is φ = 242025792.

The previous prime is 257152391. The next prime is 257152429. The reversal of 257152421 is 124251752.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 182520100 + 74632321 = 13510^2 + 8639^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257152421 is a prime.

It is a super-2 number, since 2×257152421² = 132254735252322482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257152429) 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 3 ways as a sum of consecutive naturals, for example, 7563290 + ... + 7563323.

It is an arithmetic number, because the mean of its divisors is an integer number (68069763).

Almost surely, 2^257152421 is an apocalyptic number.

It is an amenable number.

257152421 is a deficient number, since it is larger than the sum of its proper divisors (15126631).

257152421 is a wasteful number, since it uses less digits than its factorization.

257152421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15126630.

The product of its digits is 5600, while the sum is 29.

The square root of 257152421 is about 16035.9727176121. The cubic root of 257152421 is about 635.9117833487.

The spelling of 257152421 in words is "two hundred fifty-seven million, one hundred fifty-two thousand, four hundred twenty-one".