20430721100 has 18 divisors (see below), whose sum is σ = 44334665004. Its totient is φ = 8172288400.

The previous prime is 20430721097. The next prime is 20430721169. The reversal of 20430721100 is 112703402.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 102153506 + ... + 102153705.

Almost surely, 2^20430721100 is an apocalyptic number.

20430721100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20430721100 is an abundant number, since it is smaller than the sum of its proper divisors (23903943904).

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

20430721100 is a wasteful number, since it uses less digits than its factorization.

20430721100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204307225 (or 204307218 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The spelling of 20430721100 in words is "twenty billion, four hundred thirty million, seven hundred twenty-one thousand, one hundred".