257987929 has 4 divisors (see below), whose sum is σ = 258074020. Its totient is φ = 257901840.

The previous prime is 257987923. The next prime is 257987957. The reversal of 257987929 is 929789752.

257987929 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 63441225 + 194546704 = 7965^2 + 13948^2 .

It is a cyclic number.

It is not a de Polignac number, because 257987929 - 2⁵ = 257987897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257987923) 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, 38382 + ... + 44599.

It is an arithmetic number, because the mean of its divisors is an integer number (64518505).

Almost surely, 2^257987929 is an apocalyptic number.

It is an amenable number.

257987929 is a deficient number, since it is larger than the sum of its proper divisors (86091).

257987929 is an equidigital number, since it uses as much as digits as its factorization.

257987929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86090.

The product of its digits is 5715360, while the sum is 58.

The square root of 257987929 is about 16062.0026459965. The cubic root of 257987929 is about 636.5997475724.

The spelling of 257987929 in words is "two hundred fifty-seven million, nine hundred eighty-seven thousand, nine hundred twenty-nine".