21102202120 has 16 divisors (see below), whose sum is σ = 47479954860. Its totient is φ = 8440880832.

The previous prime is 21102202097. The next prime is 21102202159. The reversal of 21102202120 is 2120220112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21101048644 + 1153476 = 145262^2 + 1074^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21102202120.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263777487 + ... + 263777566.

Almost surely, 2^21102202120 is an apocalyptic number.

21102202120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102202120 is an abundant number, since it is smaller than the sum of its proper divisors (26377752740).

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

21102202120 is a wasteful number, since it uses less digits than its factorization.

21102202120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527555064 (or 527555060 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21102202120 its reverse (2120220112), we get a palindrome (23222422232).

The spelling of 21102202120 in words is "twenty-one billion, one hundred two million, two hundred two thousand, one hundred twenty".