21520445752212 has 72 divisors (see below), whose sum is σ = 57594064035648. Its totient is φ = 6237810353280.

The previous prime is 21520445752177. The next prime is 21520445752291. The reversal of 21520445752212 is 21225754402512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 322167553 + ... + 322234344.

Almost surely, 2^{21520445752212} is an apocalyptic number.

21520445752212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21520445752212 is an abundant number, since it is smaller than the sum of its proper divisors (36073618283436).

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

21520445752212 is a wasteful number, since it uses less digits than its factorization.

21520445752212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644401949 (or 644401936 counting only the distinct ones).

The product of its (nonzero) digits is 448000, while the sum is 42.

The spelling of 21520445752212 in words is "twenty-one trillion, five hundred twenty billion, four hundred forty-five million, seven hundred fifty-two thousand, two hundred twelve".