21201000100 has 72 divisors (see below), whose sum is σ = 52602883200. Its totient is φ = 7265541120.

The previous prime is 21201000091. The next prime is 21201000113. The reversal of 21201000100 is 100010212.

It is a Harshad number since it is a multiple of its sum of digits (7).

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, 1854201 + ... + 1865599.

It is an arithmetic number, because the mean of its divisors is an integer number (730595600).

Almost surely, 2^21201000100 is an apocalyptic number.

21201000100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201000100 is an abundant number, since it is smaller than the sum of its proper divisors (31401883100).

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

21201000100 is a wasteful number, since it uses less digits than its factorization.

21201000100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14077 (or 14070 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21201000100 its reverse (100010212), we get a palindrome (21301010312).

The spelling of 21201000100 in words is "twenty-one billion, two hundred one million, one hundred", and thus it is an aban number.