31907984221 has 4 divisors (see below), whose sum is σ = 31911553152. Its totient is φ = 31904415292.

The previous prime is 31907984201. The next prime is 31907984231. The reversal of 31907984221 is 12248970913.

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 31907984221 - 2¹⁹ = 31907459933 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 (31907984201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1771021 + ... + 1788946.

It is an arithmetic number, because the mean of its divisors is an integer number (7977888288).

Almost surely, 2^31907984221 is an apocalyptic number.

It is an amenable number.

31907984221 is a deficient number, since it is larger than the sum of its proper divisors (3568931).

31907984221 is an equidigital number, since it uses as much as digits as its factorization.

31907984221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3568930.

The product of its (nonzero) digits is 217728, while the sum is 46.

The spelling of 31907984221 in words is "thirty-one billion, nine hundred seven million, nine hundred eighty-four thousand, two hundred twenty-one".