21125540320 has 24 divisors (see below), whose sum is σ = 49909089384. Its totient is φ = 8450216064.

The previous prime is 21125540159. The next prime is 21125540327. The reversal of 21125540320 is 2304552112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125540327) 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 3 ways as a sum of consecutive naturals, for example, 66017154 + ... + 66017473.

It is an arithmetic number, because the mean of its divisors is an integer number (2079545391).

Almost surely, 2^21125540320 is an apocalyptic number.

21125540320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21125540320 is an abundant number, since it is smaller than the sum of its proper divisors (28783549064).

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

21125540320 is a wasteful number, since it uses less digits than its factorization.

21125540320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132034642 (or 132034634 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 21125540320 in words is "twenty-one billion, one hundred twenty-five million, five hundred forty thousand, three hundred twenty".