257220831 has 16 divisors (see below), whose sum is σ = 395622144. Its totient is φ = 145608384.

The previous prime is 257220787. The next prime is 257220851. The reversal of 257220831 is 138022752.

It is not a de Polignac number, because 257220831 - 2¹⁴ = 257204447 is a prime.

It is a super-2 number, since 2×257220831² = 132325111800661122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257220851) 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 15 ways as a sum of consecutive naturals, for example, 54990 + ... + 59483.

It is an arithmetic number, because the mean of its divisors is an integer number (24726384).

Almost surely, 2^257220831 is an apocalyptic number.

257220831 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

257220831 is a deficient number, since it is larger than the sum of its proper divisors (138401313).

257220831 is a wasteful number, since it uses less digits than its factorization.

257220831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114590.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 257220831 is about 16038.1055926191. The cubic root of 257220831 is about 635.9681686731.

The spelling of 257220831 in words is "two hundred fifty-seven million, two hundred twenty thousand, eight hundred thirty-one".