21202444100 has 36 divisors (see below), whose sum is σ = 46118681028. Its totient is φ = 8460816000.

The previous prime is 21202444061. The next prime is 21202444121. The reversal of 21202444100 is 144420212.

It can be written as a sum of positive squares in 6 ways, for example, as 2483826244 + 18718617856 = 49838^2 + 136816^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 209711 + ... + 293910.

It is an arithmetic number, because the mean of its divisors is an integer number (1281074473).

Almost surely, 2^21202444100 is an apocalyptic number.

21202444100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202444100 is an abundant number, since it is smaller than the sum of its proper divisors (24916236928).

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

21202444100 is a wasteful number, since it uses less digits than its factorization.

21202444100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 504056 (or 504049 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21202444100 its reverse (144420212), we get a palindrome (21346864312).

The spelling of 21202444100 in words is "twenty-one billion, two hundred two million, four hundred forty-four thousand, one hundred".