21044515500 has 192 divisors, whose sum is σ = 68531299200. Its totient is φ = 5575564800.

The previous prime is 21044515469. The next prime is 21044515523. The reversal of 21044515500 is 551544012.

21044515500 is a `hidden beast` number, since 2 + 104 + 4 + 5 + 1 + 550 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2114536 + ... + 2124464.

It is an arithmetic number, because the mean of its divisors is an integer number (356933850).

Almost surely, 2^21044515500 is an apocalyptic number.

21044515500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21044515500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34265649600).

21044515500 is an abundant number, since it is smaller than the sum of its proper divisors (47486783700).

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

21044515500 is a wasteful number, since it uses less digits than its factorization.

21044515500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10114 (or 10096 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The spelling of 21044515500 in words is "twenty-one billion, forty-four million, five hundred fifteen thousand, five hundred".