21201230100 has 72 divisors (see below), whose sum is σ = 63457500960. Its totient is φ = 5458705280.

The previous prime is 21201230087. The next prime is 21201230101. The reversal of 21201230100 is 103210212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201230101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1209762 + ... + 1227161.

It is an arithmetic number, because the mean of its divisors is an integer number (881354180).

Almost surely, 2^21201230100 is an apocalyptic number.

21201230100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201230100 is an abundant number, since it is smaller than the sum of its proper divisors (42256270860).

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

21201230100 is a wasteful number, since it uses less digits than its factorization.

21201230100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2436969 (or 2436962 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21201230100 its reverse (103210212), we get a palindrome (21304440312).

The spelling of 21201230100 in words is "twenty-one billion, two hundred one million, two hundred thirty thousand, one hundred".