31312609 has 4 divisors (see below), whose sum is σ = 31341616. Its totient is φ = 31283604.

The previous prime is 31312597. The next prime is 31312613. The reversal of 31312609 is 90621313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90621313 = 89 ⋅1018217.

It is a cyclic number.

It is not a de Polignac number, because 31312609 - 2⁵ = 31312577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31312679) 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, 12819 + ... + 15064.

It is an arithmetic number, because the mean of its divisors is an integer number (7835404).

Almost surely, 2^31312609 is an apocalyptic number.

It is an amenable number.

31312609 is a deficient number, since it is larger than the sum of its proper divisors (29007).

31312609 is a wasteful number, since it uses less digits than its factorization.

31312609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29006.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 31312609 is about 5595.7670609131. The cubic root of 31312609 is about 315.1904752086.

The spelling of 31312609 in words is "thirty-one million, three hundred twelve thousand, six hundred nine".