257838921 has 12 divisors (see below), whose sum is σ = 373822020. Its totient is φ = 171252000.

The previous prime is 257838899. The next prime is 257838937. The reversal of 257838921 is 129838752.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 150405696 + 107433225 = 12264^2 + 10365^2 .

It is not a de Polignac number, because 257838921 - 2¹⁰ = 257837897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (257838941) 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 11 ways as a sum of consecutive naturals, for example, 50830 + ... + 55671.

It is an arithmetic number, because the mean of its divisors is an integer number (31151835).

Almost surely, 2^257838921 is an apocalyptic number.

It is an amenable number.

257838921 is a deficient number, since it is larger than the sum of its proper divisors (115983099).

257838921 is a wasteful number, since it uses less digits than its factorization.

257838921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106776 (or 106773 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 257838921 is about 16057.3634510775. The cubic root of 257838921 is about 636.4771620905.

The spelling of 257838921 in words is "two hundred fifty-seven million, eight hundred thirty-eight thousand, nine hundred twenty-one".