21695750064 has 120 divisors (see below), whose sum is σ = 64716473952. Its totient is φ = 6761318400.

The previous prime is 21695750053. The next prime is 21695750071. The reversal of 21695750064 is 46005759612.

21695750064 is a `hidden beast` number, since 2 + 16 + 9 + 575 + 0 + 0 + 64 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 340302 + ... + 398994.

Almost surely, 2^21695750064 is an apocalyptic number.

21695750064 is a gapful number since it is divisible by the number (24) 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 21695750064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32358236976).

21695750064 is an abundant number, since it is smaller than the sum of its proper divisors (43020723888).

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

21695750064 is a wasteful number, since it uses less digits than its factorization.

21695750064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58875 (or 58866 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The spelling of 21695750064 in words is "twenty-one billion, six hundred ninety-five million, seven hundred fifty thousand, sixty-four".