21539889936 has 60 divisors (see below), whose sum is σ = 60292908988. Its totient is φ = 7178637312.

The previous prime is 21539889911. The next prime is 21539889949. The reversal of 21539889936 is 63998893512.

21539889936 is a `hidden beast` number, since 2 + 1 + 539 + 8 + 8 + 9 + 93 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7082232336 + 14457657600 = 84156^2 + 120240^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1054476 + ... + 1074708.

Almost surely, 2^21539889936 is an apocalyptic number.

It is an amenable number.

21539889936 is an abundant number, since it is smaller than the sum of its proper divisors (38753019052).

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

21539889936 is a wasteful number, since it uses less digits than its factorization.

21539889936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27640 (or 27631 counting only the distinct ones).

The product of its digits is 25194240, while the sum is 63.

The spelling of 21539889936 in words is "twenty-one billion, five hundred thirty-nine million, eight hundred eighty-nine thousand, nine hundred thirty-six".