31110021020 has 48 divisors (see below), whose sum is σ = 71014110048. Its totient is φ = 11379413760.

The previous prime is 31110021011. The next prime is 31110021031. The reversal of 31110021020 is 2012001113.

It is a junction number, because it is equal to n+sod(n) for n = 31110020992 and 31110021010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 531311 + ... + 586950.

It is an arithmetic number, because the mean of its divisors is an integer number (1479460626).

Almost surely, 2^31110021020 is an apocalyptic number.

It is an amenable number.

31110021020 is an abundant number, since it is smaller than the sum of its proper divisors (39904089028).

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

31110021020 is a wasteful number, since it uses less digits than its factorization.

31110021020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118390 (or 1118388 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 31110021020 its reverse (2012001113), we get a palindrome (33122022133).

The spelling of 31110021020 in words is "thirty-one billion, one hundred ten million, twenty-one thousand, twenty".