21959250768 has 640 divisors, whose sum is σ = 82412503040. Its totient is φ = 5441955840.

The previous prime is 21959250767. The next prime is 21959250773. The reversal of 21959250768 is 86705295912.

21959250768 is a `hidden beast` number, since 21 + 9 + 59 + 2 + 507 + 68 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21959250767) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 45090621 + ... + 45091107.

It is an arithmetic number, because the mean of its divisors is an integer number (128769536).

Almost surely, 2^21959250768 is an apocalyptic number.

21959250768 is a gapful number since it is divisible by the number (28) 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 21959250768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41206251520).

21959250768 is an abundant number, since it is smaller than the sum of its proper divisors (60453252272).

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

21959250768 is a wasteful number, since it uses less digits than its factorization.

21959250768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592 (or 580 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 21959250768 in words is "twenty-one billion, nine hundred fifty-nine million, two hundred fifty thousand, seven hundred sixty-eight".