21244012100 has 72 divisors (see below), whose sum is σ = 50635717440. Its totient is φ = 7700330880.

The previous prime is 21244012067. The next prime is 21244012121. The reversal of 21244012100 is 121044212.

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, 199367 + ... + 286766.

Almost surely, 2^21244012100 is an apocalyptic number.

21244012100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21244012100 is an abundant number, since it is smaller than the sum of its proper divisors (29391705340).

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

21244012100 is a wasteful number, since it uses less digits than its factorization.

21244012100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486189 (or 486182 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21244012100 its reverse (121044212), we get a palindrome (21365056312).

The spelling of 21244012100 in words is "twenty-one billion, two hundred forty-four million, twelve thousand, one hundred".