257421889 has 4 divisors (see below), whose sum is σ = 258300756. Its totient is φ = 256543024.

The previous prime is 257421887. The next prime is 257421919. The reversal of 257421889 is 988124752.

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 106254864 + 151167025 = 10308^2 + 12295^2 .

It is a cyclic number.

It is not a de Polignac number, because 257421889 - 2¹ = 257421887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257421887) 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, 438994 + ... + 439579.

It is an arithmetic number, because the mean of its divisors is an integer number (64575189).

Almost surely, 2^257421889 is an apocalyptic number.

It is an amenable number.

257421889 is a deficient number, since it is larger than the sum of its proper divisors (878867).

257421889 is an equidigital number, since it uses as much as digits as its factorization.

257421889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878866.

The product of its digits is 322560, while the sum is 46.

The square root of 257421889 is about 16044.3725025318. The cubic root of 257421889 is about 636.1338281263.

The spelling of 257421889 in words is "two hundred fifty-seven million, four hundred twenty-one thousand, eight hundred eighty-nine".