21688381260 has 192 divisors, whose sum is σ = 83046297600. Its totient is φ = 4575999744.

The previous prime is 21688381229. The next prime is 21688381271. The reversal of 21688381260 is 6218388612.

21688381260 is a `hidden beast` number, since 2 + 1 + 6 + 8 + 8 + 381 + 260 = 666.

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

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, 171540 + ... + 269819.

It is an arithmetic number, because the mean of its divisors is an integer number (432532800).

Almost surely, 2^21688381260 is an apocalyptic number.

21688381260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21688381260 is an abundant number, since it is smaller than the sum of its proper divisors (61357916340).

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

21688381260 is a wasteful number, since it uses less digits than its factorization.

21688381260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441397 (or 441389 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 21688381260 in words is "twenty-one billion, six hundred eighty-eight million, three hundred eighty-one thousand, two hundred sixty".