31986729 has 6 divisors (see below), whose sum is σ = 46203066. Its totient is φ = 21324480.

The previous prime is 31986727. The next prime is 31986769. The reversal of 31986729 is 92768913.

It can be written as a sum of positive squares in only one way, i.e., 21874329 + 10112400 = 4677^2 + 3180^2 .

It is not a de Polignac number, because 31986729 - 2¹ = 31986727 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31986727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1777032 + ... + 1777049.

It is an arithmetic number, because the mean of its divisors is an integer number (7700511).

Almost surely, 2^31986729 is an apocalyptic number.

It is an amenable number.

31986729 is a deficient number, since it is larger than the sum of its proper divisors (14216337).

31986729 is a wasteful number, since it uses less digits than its factorization.

31986729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3554087 (or 3554084 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 31986729 is about 5655.6811260891. The cubic root of 31986729 is about 317.4363159931.

The spelling of 31986729 in words is "thirty-one million, nine hundred eighty-six thousand, seven hundred twenty-nine".