21030120100 has 36 divisors (see below), whose sum is σ = 49784032368. Its totient is φ = 7647316000.

The previous prime is 21030120091. The next prime is 21030120109. The reversal of 21030120100 is 102103012.

It is an interprime number because it is at equal distance from previous prime (21030120091) and next prime (21030120109).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21030120109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9558046 + ... + 9560245.

It is an arithmetic number, because the mean of its divisors is an integer number (1382889788).

Almost surely, 2^21030120100 is an apocalyptic number.

21030120100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21030120100 is an abundant number, since it is smaller than the sum of its proper divisors (28753912268).

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

21030120100 is a wasteful number, since it uses less digits than its factorization.

21030120100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19118316 (or 19118309 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

Adding to 21030120100 its reverse (102103012), we get a palindrome (21132223112).

The spelling of 21030120100 in words is "twenty-one billion, thirty million, one hundred twenty thousand, one hundred".