21125957760 has 128 divisors (see below), whose sum is σ = 74821161600. Its totient is φ = 5633584128.

The previous prime is 21125957731. The next prime is 21125957767. The reversal of 21125957760 is 6775952112.

21125957760 is a `hidden beast` number, since 2 + 1 + 12 + 5 + 9 + 577 + 60 = 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 (45).

It is not an unprimeable number, because it can be changed into a prime (21125957767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 594004 + ... + 628563.

It is an arithmetic number, because the mean of its divisors is an integer number (584540325).

Almost surely, 2^21125957760 is an apocalyptic number.

21125957760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21125957760 is an abundant number, since it is smaller than the sum of its proper divisors (53695203840).

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

21125957760 is a wasteful number, since it uses less digits than its factorization.

21125957760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222595 (or 1222577 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 45.

The spelling of 21125957760 in words is "twenty-one billion, one hundred twenty-five million, nine hundred fifty-seven thousand, seven hundred sixty".