21641757696 has 264 divisors, whose sum is σ = 69479830784. Its totient is φ = 6443089920.

The previous prime is 21641757671. The next prime is 21641757733. The reversal of 21641757696 is 69675714612.

21641757696 is a `hidden beast` number, since 2 + 1 + 64 + 1 + 7 + 576 + 9 + 6 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3711135 + ... + 3716961.

Almost surely, 2^21641757696 is an apocalyptic number.

21641757696 is a gapful number since it is divisible by the number (26) 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 21641757696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34739915392).

21641757696 is an abundant number, since it is smaller than the sum of its proper divisors (47838073088).

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

21641757696 is a wasteful number, since it uses less digits than its factorization.

21641757696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5897 (or 5876 counting only the distinct ones).

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

The spelling of 21641757696 in words is "twenty-one billion, six hundred forty-one million, seven hundred fifty-seven thousand, six hundred ninety-six".