21653804700 has 216 divisors, whose sum is σ = 74809534800. Its totient is φ = 5195059200.

The previous prime is 21653804617. The next prime is 21653804707. The reversal of 21653804700 is 740835612.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21653804707) 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 71 ways as a sum of consecutive naturals, for example, 949026 + ... + 971574.

Almost surely, 2^21653804700 is an apocalyptic number.

21653804700 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 21653804700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37404767400).

21653804700 is an abundant number, since it is smaller than the sum of its proper divisors (53155730100).

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

21653804700 is a wasteful number, since it uses less digits than its factorization.

21653804700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22677 (or 22667 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 21653804700 in words is "twenty-one billion, six hundred fifty-three million, eight hundred four thousand, seven hundred".