31689907 has 4 divisors (see below), whose sum is σ = 31997680. Its totient is φ = 31382136.

The previous prime is 31689893. The next prime is 31689923. The reversal of 31689907 is 70998613.

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

It is a cyclic number.

It is not a de Polignac number, because 31689907 - 2¹⁵ = 31657139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31689407) 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, 153732 + ... + 153937.

It is an arithmetic number, because the mean of its divisors is an integer number (7999420).

Almost surely, 2^31689907 is an apocalyptic number.

31689907 is a deficient number, since it is larger than the sum of its proper divisors (307773).

31689907 is a wasteful number, since it uses less digits than its factorization.

31689907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307772.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 31689907 is about 5629.3789177848. The cubic root of 31689907 is about 316.4513758558.

The spelling of 31689907 in words is "thirty-one million, six hundred eighty-nine thousand, nine hundred seven".