21759725520 has 160 divisors (see below), whose sum is σ = 80715667200. Its totient is φ = 5356233216.

The previous prime is 21759725459. The next prime is 21759725521. The reversal of 21759725520 is 2552795712.

21759725520 is a `hidden beast` number, since 2 + 1 + 7 + 5 + 97 + 2 + 552 + 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 not an unprimeable number, because it can be changed into a prime (21759725521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 359380 + ... + 415539.

It is an arithmetic number, because the mean of its divisors is an integer number (504472920).

Almost surely, 2^21759725520 is an apocalyptic number.

21759725520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21759725520 is an abundant number, since it is smaller than the sum of its proper divisors (58955941680).

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

21759725520 is a wasteful number, since it uses less digits than its factorization.

21759725520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774954 (or 774942 counting only the distinct ones).

The product of its (nonzero) digits is 441000, while the sum is 45.

The spelling of 21759725520 in words is "twenty-one billion, seven hundred fifty-nine million, seven hundred twenty-five thousand, five hundred twenty".