21587775072 has 192 divisors, whose sum is σ = 60948599040. Its totient is φ = 6670080000.

The previous prime is 21587775043. The next prime is 21587775089. The reversal of 21587775072 is 27057778512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27926878 + ... + 27927650.

It is an arithmetic number, because the mean of its divisors is an integer number (317440620).

Almost surely, 2^21587775072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21587775072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30474299520).

21587775072 is an abundant number, since it is smaller than the sum of its proper divisors (39360823968).

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

21587775072 is a wasteful number, since it uses less digits than its factorization.

21587775072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1117 (or 1109 counting only the distinct ones).

The product of its (nonzero) digits is 1920800, while the sum is 51.

The spelling of 21587775072 in words is "twenty-one billion, five hundred eighty-seven million, seven hundred seventy-five thousand, seventy-two".