31645013 has 4 divisors (see below), whose sum is σ = 33310560. Its totient is φ = 29979468.

The previous prime is 31644979. The next prime is 31645021. The reversal of 31645013 is 31054613.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 31645013 - 2¹⁴ = 31628629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31645013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31645043) 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, 832745 + ... + 832782.

It is an arithmetic number, because the mean of its divisors is an integer number (8327640).

Almost surely, 2^31645013 is an apocalyptic number.

It is an amenable number.

31645013 is a deficient number, since it is larger than the sum of its proper divisors (1665547).

31645013 is a wasteful number, since it uses less digits than its factorization.

31645013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1665546.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 31645013 is about 5625.3900309223. The cubic root of 31645013 is about 316.3018699779.

Subtracting from 31645013 its sum of digits (23), we obtain a triangular number (31644990 = T₇₉₅₅).

Adding to 31645013 its reverse (31054613), we get a palindrome (62699626).

The spelling of 31645013 in words is "thirty-one million, six hundred forty-five thousand, thirteen".