31212100000000 has 162 divisors, whose sum is σ = 77878056806102. Its totient is φ = 12484800000000.

The previous prime is 31212099999979. The next prime is 31212100000019. The reversal of 31212100000000 is 121213.

It can be written as a sum of positive squares in 9 ways, for example, as 18798259804416 + 12413840195584 = 4335696^2 + 3523328^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 99843940 + ... + 100156060.

Almost surely, 2^{31212100000000} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31212100000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38939028403051).

31212100000000 is an abundant number, since it is smaller than the sum of its proper divisors (46665956806102).

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

31212100000000 is an frugal number, since it uses more digits than its factorization.

31212100000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312177 (or 312128 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

Adding to 31212100000000 its reverse (121213), we get a palindrome (31212100121213).

The spelling of 31212100000000 in words is "thirty-one trillion, two hundred twelve billion, one hundred million", and thus it is an aban number.