21706897536 has 128 divisors (see below), whose sum is σ = 64425240000. Its totient is φ = 7195004928.

The previous prime is 21706897523. The next prime is 21706897543. The reversal of 21706897536 is 63579860712.

21706897536 is a `hidden beast` number, since 2 + 17 + 0 + 6 + 8 + 97 + 536 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 601080 + ... + 636168.

Almost surely, 2^21706897536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21706897536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32212620000).

21706897536 is an abundant number, since it is smaller than the sum of its proper divisors (42718342464).

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

21706897536 is a wasteful number, since it uses less digits than its factorization.

21706897536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35291 (or 35273 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 21706897536 in words is "twenty-one billion, seven hundred six million, eight hundred ninety-seven thousand, five hundred thirty-six".