31213020402 has 48 divisors (see below), whose sum is σ = 69512202240. Its totient is φ = 10114950816.

The previous prime is 31213020401. The next prime is 31213020407. The reversal of 31213020402 is 20402031213.

31213020402 is a `hidden beast` number, since 31 + 213 + 0 + 20 + 402 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (31213020401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 833493 + ... + 870135.

It is an arithmetic number, because the mean of its divisors is an integer number (1448170880).

Almost surely, 2^31213020402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31213020402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34756101120).

31213020402 is an abundant number, since it is smaller than the sum of its proper divisors (38299181838).

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

31213020402 is a wasteful number, since it uses less digits than its factorization.

31213020402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37967 (or 37964 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 31213020402 its reverse (20402031213), we get a palindrome (51615051615).

The spelling of 31213020402 in words is "thirty-one billion, two hundred thirteen million, twenty thousand, four hundred two".