21571090596 has 108 divisors (see below), whose sum is σ = 60917836252. Its totient is φ = 6429456000.

The previous prime is 21571090571. The next prime is 21571090643. The reversal of 21571090596 is 69509017512.

21571090596 is a `hidden beast` number, since 2 + 1 + 57 + 1 + 0 + 9 + 0 + 596 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5912072100 + 15659018496 = 76890^2 + 125136^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 225126 + ... + 306306.

Almost surely, 2^21571090596 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 21571090596, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30458918126).

21571090596 is an abundant number, since it is smaller than the sum of its proper divisors (39346745656).

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

21571090596 is a wasteful number, since it uses less digits than its factorization.

21571090596 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81274 (or 81258 counting only the distinct ones).

The product of its (nonzero) digits is 170100, while the sum is 45.

Adding to 21571090596 its sum of digits (45), we get a square (21571090641 = 146871²).

The spelling of 21571090596 in words is "twenty-one billion, five hundred seventy-one million, ninety thousand, five hundred ninety-six".