21706392960 has 768 divisors, whose sum is σ = 90105200640. Its totient is φ = 4891041792.

The previous prime is 21706392919. The next prime is 21706392973. The reversal of 21706392960 is 6929360712.

It is a happy number.

21706392960 is a `hidden beast` number, since 2 + 1 + 7 + 0 + 639 + 2 + 9 + 6 + 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 an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 138257202 + ... + 138257358.

It is an arithmetic number, because the mean of its divisors is an integer number (117324480).

Almost surely, 2^21706392960 is an apocalyptic number.

21706392960 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 21706392960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45052600320).

21706392960 is an abundant number, since it is smaller than the sum of its proper divisors (68398807680).

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

21706392960 is a wasteful number, since it uses less digits than its factorization.

21706392960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325 (or 301 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The spelling of 21706392960 in words is "twenty-one billion, seven hundred six million, three hundred ninety-two thousand, nine hundred sixty".