21750577506 has 96 divisors (see below), whose sum is σ = 55967708160. Its totient is φ = 5973028992.

The previous prime is 21750577481. The next prime is 21750577543. The reversal of 21750577506 is 60577505712.

It is a happy number.

21750577506 is a `hidden beast` number, since 2 + 1 + 75 + 0 + 5 + 77 + 506 = 666.

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 47 ways as a sum of consecutive naturals, for example, 801496 + ... + 828188.

It is an arithmetic number, because the mean of its divisors is an integer number (582996960).

Almost surely, 2^21750577506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21750577506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27983854080).

21750577506 is an abundant number, since it is smaller than the sum of its proper divisors (34217130654).

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

21750577506 is a wasteful number, since it uses less digits than its factorization.

21750577506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26960 (or 26957 counting only the distinct ones).

The product of its (nonzero) digits is 514500, while the sum is 45.

The spelling of 21750577506 in words is "twenty-one billion, seven hundred fifty million, five hundred seventy-seven thousand, five hundred six".