257720371 has 8 divisors (see below), whose sum is σ = 264751344. Its totient is φ = 250736640.

The previous prime is 257720347. The next prime is 257720381. The reversal of 257720371 is 173027752.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 257720371 - 2⁹ = 257719859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (257720341) 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 7 ways as a sum of consecutive naturals, for example, 610 + ... + 22711.

It is an arithmetic number, because the mean of its divisors is an integer number (33093918).

Almost surely, 2^257720371 is an apocalyptic number.

257720371 is a deficient number, since it is larger than the sum of its proper divisors (7030973).

257720371 is a wasteful number, since it uses less digits than its factorization.

257720371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23621.

The product of its (nonzero) digits is 20580, while the sum is 34.

The square root of 257720371 is about 16053.6715738176. The cubic root of 257720371 is about 636.3795999712.

The spelling of 257720371 in words is "two hundred fifty-seven million, seven hundred twenty thousand, three hundred seventy-one".