21225055212 has 24 divisors (see below), whose sum is σ = 55027921200. Its totient is φ = 7075018368.

The previous prime is 21225055177. The next prime is 21225055259. The reversal of 21225055212 is 21255052212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98264037 + ... + 98264252.

It is an arithmetic number, because the mean of its divisors is an integer number (2292830050).

Almost surely, 2^21225055212 is an apocalyptic number.

It is an amenable number.

21225055212 is an abundant number, since it is smaller than the sum of its proper divisors (33802865988).

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

21225055212 is a wasteful number, since it uses less digits than its factorization.

21225055212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196528302 (or 196528294 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The spelling of 21225055212 in words is "twenty-one billion, two hundred twenty-five million, fifty-five thousand, two hundred twelve".