257427421 has 4 divisors (see below), whose sum is σ = 257528700. Its totient is φ = 257326144.

The previous prime is 257427407. The next prime is 257427433. The reversal of 257427421 is 124724752.

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 50211396 + 207216025 = 7086^2 + 14395^2 .

It is a cyclic number.

It is not a de Polignac number, because 257427421 - 2⁹ = 257426909 is a prime.

It is a super-2 number, since 2×257427421² = 132537754165422482, 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 (257427491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46726 + ... + 51943.

It is an arithmetic number, because the mean of its divisors is an integer number (64382175).

Almost surely, 2^257427421 is an apocalyptic number.

It is an amenable number.

257427421 is a deficient number, since it is larger than the sum of its proper divisors (101279).

257427421 is an equidigital number, since it uses as much as digits as its factorization.

257427421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101278.

The product of its digits is 31360, while the sum is 34.

The square root of 257427421 is about 16044.5448985005. The cubic root of 257427421 is about 636.1383849353.

The spelling of 257427421 in words is "two hundred fifty-seven million, four hundred twenty-seven thousand, four hundred twenty-one".