21095889540 has 96 divisors (see below), whose sum is σ = 64668240000. Its totient is φ = 5095910400.

The previous prime is 21095889533. The next prime is 21095889571. The reversal of 21095889540 is 4598859012.

It is an unprimeable number.

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, 128586 + ... + 242334.

It is an arithmetic number, because the mean of its divisors is an integer number (673627500).

Almost surely, 2^21095889540 is an apocalyptic number.

21095889540 is a gapful number since it is divisible by the number (20) 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 21095889540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32334120000).

21095889540 is an abundant number, since it is smaller than the sum of its proper divisors (43572350460).

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

21095889540 is a wasteful number, since it uses less digits than its factorization.

21095889540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114053 (or 114051 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 51.

The spelling of 21095889540 in words is "twenty-one billion, ninety-five million, eight hundred eighty-nine thousand, five hundred forty".