257561667 has 16 divisors (see below), whose sum is σ = 416261760. Its totient is φ = 156097800.

The previous prime is 257561627. The next prime is 257561669. The reversal of 257561667 is 766165752.

257561667 is a `hidden beast` number, since 2 + 575 + 6 + 16 + 67 = 666.

It is not a de Polignac number, because 257561667 - 2¹¹ = 257559619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (257561669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 433309 + ... + 433902.

It is an arithmetic number, because the mean of its divisors is an integer number (26016360).

Almost surely, 2^257561667 is an apocalyptic number.

257561667 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

257561667 is a deficient number, since it is larger than the sum of its proper divisors (158700093).

257561667 is a wasteful number, since it uses less digits than its factorization.

257561667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867231 (or 867225 counting only the distinct ones).

The product of its digits is 529200, while the sum is 45.

The square root of 257561667 is about 16048.7278935123. The cubic root of 257561667 is about 636.2489457977.

The spelling of 257561667 in words is "two hundred fifty-seven million, five hundred sixty-one thousand, six hundred sixty-seven".