21201022228 has 12 divisors (see below), whose sum is σ = 38381161140. Its totient is φ = 10234976192.

The previous prime is 21201022147. The next prime is 21201022229. The reversal of 21201022228 is 82222010212.

It can be written as a sum of positive squares in 2 ways, for example, as 17129050884 + 4071971344 = 130878^2 + 63812^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21201022199 and 21201022208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201022229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91383601 + ... + 91383832.

It is an arithmetic number, because the mean of its divisors is an integer number (3198430095).

Almost surely, 2^21201022228 is an apocalyptic number.

It is an amenable number.

21201022228 is a deficient number, since it is larger than the sum of its proper divisors (17180138912).

21201022228 is a wasteful number, since it uses less digits than its factorization.

21201022228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182767466 (or 182767464 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

The spelling of 21201022228 in words is "twenty-one billion, two hundred one million, twenty-two thousand, two hundred twenty-eight".