309979640 has 16 divisors (see below), whose sum is σ = 697454280. Its totient is φ = 123991840.

The previous prime is 309979603. The next prime is 309979651. The reversal of 309979640 is 46979903.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3874706 + ... + 3874785.

Almost surely, 2^309979640 is an apocalyptic number.

It is an amenable number.

309979640 is an abundant number, since it is smaller than the sum of its proper divisors (387474640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

309979640 is a wasteful number, since it uses less digits than its factorization.

309979640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7749502 (or 7749498 counting only the distinct ones).

The product of its (nonzero) digits is 367416, while the sum is 47.

The square root of 309979640 is about 17606.2386670180. The cubic root of 309979640 is about 676.7751282806.

The spelling of 309979640 in words is "three hundred nine million, nine hundred seventy-nine thousand, six hundred forty".