257421919 has 2 divisors, whose sum is σ = 257421920. Its totient is φ = 257421918.

The previous prime is 257421887. The next prime is 257421929. The reversal of 257421919 is 919124752.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257421919 - 2⁵ = 257421887 is a prime.

It is a super-2 number, since 2×257421919² = 132532088763285122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257421929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128710959 + 128710960.

It is an arithmetic number, because the mean of its divisors is an integer number (128710960).

Almost surely, 2^257421919 is an apocalyptic number.

257421919 is a deficient number, since it is larger than the sum of its proper divisors (1).

257421919 is an equidigital number, since it uses as much as digits as its factorization.

257421919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 40.

The square root of 257421919 is about 16044.3734374391. The cubic root of 257421919 is about 636.1338528381.

The spelling of 257421919 in words is "two hundred fifty-seven million, four hundred twenty-one thousand, nine hundred nineteen".