31987013 has 16 divisors (see below), whose sum is σ = 35925120. Its totient is φ = 28302336.

The previous prime is 31987001. The next prime is 31987019. The reversal of 31987013 is 31078913.

It is a cyclic number.

It is not a de Polignac number, because 31987013 - 2²⁰ = 30938437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31987019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53645 + ... + 54237.

It is an arithmetic number, because the mean of its divisors is an integer number (2245320).

Almost surely, 2^31987013 is an apocalyptic number.

It is an amenable number.

31987013 is a deficient number, since it is larger than the sum of its proper divisors (3938107).

31987013 is a wasteful number, since it uses less digits than its factorization.

31987013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 31987013 is about 5655.7062335309. The cubic root of 31987013 is about 317.4372554624.

The spelling of 31987013 in words is "thirty-one million, nine hundred eighty-seven thousand, thirteen".