31121302120 has 16 divisors (see below), whose sum is σ = 70022929860. Its totient is φ = 12448520832.

The previous prime is 31121302081. The next prime is 31121302183. The reversal of 31121302120 is 2120312113.

It can be written as a sum of positive squares in 2 ways, for example, as 30606102916 + 515199204 = 174946^2 + 22698^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31121302094 and 31121302103.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 389016237 + ... + 389016316.

Almost surely, 2^31121302120 is an apocalyptic number.

It is an amenable number.

31121302120 is an abundant number, since it is smaller than the sum of its proper divisors (38901627740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31121302120 is a wasteful number, since it uses less digits than its factorization.

31121302120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778032564 (or 778032560 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31121302120 its reverse (2120312113), we get a palindrome (33241614233).

The spelling of 31121302120 in words is "thirty-one billion, one hundred twenty-one million, three hundred two thousand, one hundred twenty".