309642331 has 4 divisors (see below), whose sum is σ = 311902632. Its totient is φ = 307382032.

The previous prime is 309642329. The next prime is 309642337. The reversal of 309642331 is 133246903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133246903 = 307 ⋅434029.

It is a cyclic number.

It is not a de Polignac number, because 309642331 - 2¹ = 309642329 is a prime.

It is a super-2 number, since 2×309642331² = 191756746294227122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 309642293 and 309642302.

It is not an unprimeable number, because it can be changed into a prime (309642337) 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, 1129945 + ... + 1130218.

It is an arithmetic number, because the mean of its divisors is an integer number (77975658).

Almost surely, 2^309642331 is an apocalyptic number.

309642331 is a deficient number, since it is larger than the sum of its proper divisors (2260301).

309642331 is a wasteful number, since it uses less digits than its factorization.

309642331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2260300.

The product of its (nonzero) digits is 11664, while the sum is 31.

The square root of 309642331 is about 17596.6568131563. The cubic root of 309642331 is about 676.5295581793.

The spelling of 309642331 in words is "three hundred nine million, six hundred forty-two thousand, three hundred thirty-one".