21121023100 has 72 divisors (see below), whose sum is σ = 46132078608. Its totient is φ = 8393395200.

The previous prime is 21121023041. The next prime is 21121023109. The reversal of 21121023100 is 132012112.

It is a super-2 number, since 2×21121023100² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121023109) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14145954 + ... + 14147446.

It is an arithmetic number, because the mean of its divisors is an integer number (640723314).

Almost surely, 2^21121023100 is an apocalyptic number.

21121023100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121023100 is an abundant number, since it is smaller than the sum of its proper divisors (25011055508).

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

21121023100 is a wasteful number, since it uses less digits than its factorization.

21121023100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2335 (or 2328 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21121023100 its reverse (132012112), we get a palindrome (21253035212).

The spelling of 21121023100 in words is "twenty-one billion, one hundred twenty-one million, twenty-three thousand, one hundred".