309631442 has 4 divisors (see below), whose sum is σ = 464447166. Its totient is φ = 154815720.

The previous prime is 309631423. The next prime is 309631447. The reversal of 309631442 is 244136903.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 297528001 + 12103441 = 17249^2 + 3479^2 .

It is a junction number, because it is equal to n+sod(n) for n = 309631399 and 309631408.

It is not an unprimeable number, because it can be changed into a prime (309631447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77407859 + ... + 77407862.

Almost surely, 2^309631442 is an apocalyptic number.

309631442 is a deficient number, since it is larger than the sum of its proper divisors (154815724).

309631442 is a wasteful number, since it uses less digits than its factorization.

309631442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154815723.

The product of its (nonzero) digits is 15552, while the sum is 32.

The square root of 309631442 is about 17596.3474050725. The cubic root of 309631442 is about 676.5216277211.

The spelling of 309631442 in words is "three hundred nine million, six hundred thirty-one thousand, four hundred forty-two".