21201212112100 has 36 divisors (see below), whose sum is σ = 46006910966464. Its totient is φ = 8480433106080.

The previous prime is 21201212112079. The next prime is 21201212112137. The reversal of 21201212112100 is 121121210212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18707857 + ... + 19808743.

Almost surely, 2^{21201212112100} is an apocalyptic number.

21201212112100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201212112100 is an abundant number, since it is smaller than the sum of its proper divisors (24805698854364).

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

21201212112100 is a wasteful number, since it uses less digits than its factorization.

21201212112100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1293484 (or 1293477 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21201212112100 its reverse (121121210212), we get a palindrome (21322333322312).

The spelling of 21201212112100 in words is "twenty-one trillion, two hundred one billion, two hundred twelve million, one hundred twelve thousand, one hundred".