31609431 has 24 divisors (see below), whose sum is σ = 52490880. Its totient is φ = 17955216.

The previous prime is 31609393. The next prime is 31609451. The reversal of 31609431 is 13490613.

It is not a de Polignac number, because 31609431 - 2¹⁴ = 31593047 is a prime.

It is a super-2 number, since 2×31609431² = 1998312256287522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31609395 and 31609404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31609451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9876 + ... + 12678.

It is an arithmetic number, because the mean of its divisors is an integer number (2187120).

Almost surely, 2^31609431 is an apocalyptic number.

31609431 is a deficient number, since it is larger than the sum of its proper divisors (20881449).

31609431 is a wasteful number, since it uses less digits than its factorization.

31609431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2995 (or 2992 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 31609431 is about 5622.2265162478. The cubic root of 31609431 is about 316.1832744184.

The spelling of 31609431 in words is "thirty-one million, six hundred nine thousand, four hundred thirty-one".