257352421 has 4 divisors (see below), whose sum is σ = 265654144. Its totient is φ = 249050700.

The previous prime is 257352413. The next prime is 257352437. The reversal of 257352421 is 124253752.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 257352421 - 2³ = 257352413 is a prime.

It is a super-2 number, since 2×257352421² = 132460537189122482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 8301691 = 257352421 / (2 + 5 + 7 + 3 + 5 + 2 + 4 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257302421) 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, 4150815 + ... + 4150876.

It is an arithmetic number, because the mean of its divisors is an integer number (66413536).

Almost surely, 2^257352421 is an apocalyptic number.

It is an amenable number.

257352421 is a deficient number, since it is larger than the sum of its proper divisors (8301723).

257352421 is an equidigital number, since it uses as much as digits as its factorization.

257352421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8301722.

The product of its digits is 16800, while the sum is 31.

The square root of 257352421 is about 16042.2074852559. The cubic root of 257352421 is about 636.0766005136.

The spelling of 257352421 in words is "two hundred fifty-seven million, three hundred fifty-two thousand, four hundred twenty-one".