21373688700 has 720 divisors, whose sum is σ = 86388470784. Its totient is φ = 4450982400.

The previous prime is 21373688641. The next prime is 21373688701. The reversal of 21373688700 is 788637312.

21373688700 is a `hidden beast` number, since 213 + 7 + 368 + 8 + 70 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21373688701) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 78869565 + ... + 78869835.

Almost surely, 2^21373688700 is an apocalyptic number.

21373688700 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 21373688700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43194235392).

21373688700 is an abundant number, since it is smaller than the sum of its proper divisors (65014782084).

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

21373688700 is a wasteful number, since it uses less digits than its factorization.

21373688700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 21373688700 in words is "twenty-one billion, three hundred seventy-three million, six hundred eighty-eight thousand, seven hundred".