21211012100 has 18 divisors (see below), whose sum is σ = 46027896474. Its totient is φ = 8484404800.

The previous prime is 21211012099. The next prime is 21211012117. The reversal of 21211012100 is 121011212.

It can be written as a sum of positive squares in 3 ways, for example, as 7628974336 + 13582037764 = 87344^2 + 116542^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106054961 + ... + 106055160.

Almost surely, 2^21211012100 is an apocalyptic number.

21211012100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211012100 is an abundant number, since it is smaller than the sum of its proper divisors (24816884374).

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

21211012100 is a wasteful number, since it uses less digits than its factorization.

21211012100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212110135 (or 212110128 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21211012100 its reverse (121011212), we get a palindrome (21332023312).

The spelling of 21211012100 in words is "twenty-one billion, two hundred eleven million, twelve thousand, one hundred".