21213511531212 has 192 divisors, whose sum is σ = 68750807731200. Its totient is φ = 4910771819520.

The previous prime is 21213511531181. The next prime is 21213511531243.

21213511531212 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (21213511531181) and next prime (21213511531243).

It is a self number, because there is not a number n which added to its sum of digits gives 21213511531212.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30100387 + ... + 30797082.

It is an arithmetic number, because the mean of its divisors is an integer number (358077123600).

Almost surely, 2^{21213511531212} is an apocalyptic number.

21213511531212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21213511531212 is an abundant number, since it is smaller than the sum of its proper divisors (47537296199988).

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

21213511531212 is a wasteful number, since it uses less digits than its factorization.

21213511531212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60897536 (or 60897534 counting only the distinct ones).

The product of its digits is 3600, while the sum is 30.

It can be divided in two parts, 2121351 and 1531212, that added together give a palindrome (3652563).

The spelling of 21213511531212 in words is "twenty-one trillion, two hundred thirteen billion, five hundred eleven million, five hundred thirty-one thousand, two hundred twelve".