31866013 has 2 divisors, whose sum is σ = 31866014. Its totient is φ = 31866012.

The previous prime is 31866001. The next prime is 31866049. The reversal of 31866013 is 31066813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26234884 + 5631129 = 5122^2 + 2373^2 .

It is a cyclic number.

It is not a de Polignac number, because 31866013 - 2¹³ = 31857821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31866073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15933006 + 15933007.

It is an arithmetic number, because the mean of its divisors is an integer number (15933007).

Almost surely, 2^31866013 is an apocalyptic number.

It is an amenable number.

31866013 is a deficient number, since it is larger than the sum of its proper divisors (1).

31866013 is an equidigital number, since it uses as much as digits as its factorization.

31866013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 31866013 is about 5644.9989371124. The cubic root of 31866013 is about 317.0364840400.

The spelling of 31866013 in words is "thirty-one million, eight hundred sixty-six thousand, thirteen".