249640665 has 32 divisors (see below), whose sum is σ = 434367360. Its totient is φ = 121918464.

The previous prime is 249640621. The next prime is 249640667. The reversal of 249640665 is 566046942.

It is not a de Polignac number, because 249640665 - 2⁷ = 249640537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (249640667) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3795 + ... + 22664.

It is an arithmetic number, because the mean of its divisors is an integer number (13573980).

Almost surely, 2^249640665 is an apocalyptic number.

It is an amenable number.

249640665 is a deficient number, since it is larger than the sum of its proper divisors (184726695).

249640665 is a wasteful number, since it uses less digits than its factorization.

249640665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26521.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 249640665 is about 15800.0210442898. The cubic root of 249640665 is about 629.6585577377.

The spelling of 249640665 in words is "two hundred forty-nine million, six hundred forty thousand, six hundred sixty-five".