257649 has 8 divisors (see below), whose sum is σ = 392640. Its totient is φ = 147216.

The previous prime is 257639. The next prime is 257657. The reversal of 257649 is 946752.

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

It is not a de Polignac number, because 257649 - 2¹² = 253553 is a prime.

257649 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (257639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6114 + ... + 6155.

It is an arithmetic number, because the mean of its divisors is an integer number (49080).

2²⁵⁷⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

257649 is a deficient number, since it is larger than the sum of its proper divisors (134991).

257649 is a wasteful number, since it uses less digits than its factorization.

257649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12279.

The product of its digits is 15120, while the sum is 33.

The square root of 257649 is about 507.5913710850. The cubic root of 257649 is about 63.6320849937.

The spelling of 257649 in words is "two hundred fifty-seven thousand, six hundred forty-nine".