31213031020 has 48 divisors (see below), whose sum is σ = 66067092000. Its totient is φ = 12386350080.

The previous prime is 31213030987. The next prime is 31213031023. The reversal of 31213031020 is 2013031213.

It is a junction number, because it is equal to n+sod(n) for n = 31213030985 and 31213031003.

It is not an unprimeable number, because it can be changed into a prime (31213031023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4836756 + ... + 4843204.

It is an arithmetic number, because the mean of its divisors is an integer number (1376397750).

Almost surely, 2^31213031020 is an apocalyptic number.

It is an amenable number.

31213031020 is an abundant number, since it is smaller than the sum of its proper divisors (34854060980).

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

31213031020 is a wasteful number, since it uses less digits than its factorization.

31213031020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8338 (or 8336 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 31213031020 its reverse (2013031213), we get a palindrome (33226062233).

The spelling of 31213031020 in words is "thirty-one billion, two hundred thirteen million, thirty-one thousand, twenty".