21688071874560 has 4320 divisors, whose sum is σ = 103727066002560. Its totient is φ = 4235797463040.

The previous prime is 21688071874559. The next prime is 21688071874561. The reversal of 21688071874560 is 6547817088612.

It is a happy number.

21688071874560 is a `hidden beast` number, since 2 + 1 + 68 + 8 + 0 + 7 + 1 + 8 + 7 + 4 + 560 = 666.

It is an interprime number because it is at equal distance from previous prime (21688071874559) and next prime (21688071874561).

It is a tau number, because it is divible by the number of its divisors (4320).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21688071874561) by changing a digit.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 699615221745 + ... + 699615221775.

It is an arithmetic number, because the mean of its divisors is an integer number (24010894908).

Almost surely, 2^{21688071874560} is an apocalyptic number.

21688071874560 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 21688071874560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51863533001280).

21688071874560 is an abundant number, since it is smaller than the sum of its proper divisors (82038994128000).

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

21688071874560 is a wasteful number, since it uses less digits than its factorization.

21688071874560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 36126720, while the sum is 63.

The spelling of 21688071874560 in words is "twenty-one trillion, six hundred eighty-eight billion, seventy-one million, eight hundred seventy-four thousand, five hundred sixty".