31212100220 has 48 divisors (see below), whose sum is σ = 74924111808. Its totient is φ = 10699138560.

The previous prime is 31212100207. The next prime is 31212100237. The reversal of 31212100220 is 2200121213.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 31212100195 and 31212100204.

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, 777440 + ... + 816600.

It is an arithmetic number, because the mean of its divisors is an integer number (1560918996).

Almost surely, 2^31212100220 is an apocalyptic number.

It is an amenable number.

31212100220 is an abundant number, since it is smaller than the sum of its proper divisors (43712011588).

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

31212100220 is a wasteful number, since it uses less digits than its factorization.

31212100220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44870 (or 44868 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 31212100220 its reverse (2200121213), we get a palindrome (33412221433).

The spelling of 31212100220 in words is "thirty-one billion, two hundred twelve million, one hundred thousand, two hundred twenty".