21222021210100 has 36 divisors (see below), whose sum is σ = 46056578685964. Its totient is φ = 8487925044480.

The previous prime is 21222021210077. The next prime is 21222021210163. The reversal of 21222021210100 is 101212022212.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 2632454330256 + 18589566879844 = 1622484^2 + 4311562^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10076889 + ... + 11999488.

Almost surely, 2^{21222021210100} is an apocalyptic number.

21222021210100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222021210100 is an abundant number, since it is smaller than the sum of its proper divisors (24834557475864).

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

21222021210100 is a wasteful number, since it uses less digits than its factorization.

21222021210100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22086004 (or 22085997 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21222021210100 its reverse (101212022212), we get a palindrome (21323233232312).

The spelling of 21222021210100 in words is "twenty-one trillion, two hundred twenty-two billion, twenty-one million, two hundred ten thousand, one hundred".