21609985392 has 30 divisors (see below), whose sum is σ = 60477945632. Its totient is φ = 7203328416.

The previous prime is 21609985373. The next prime is 21609985429. The reversal of 21609985392 is 29358990612.

It is a happy number.

21609985392 is a `hidden beast` number, since 2 + 16 + 0 + 9 + 98 + 539 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 75034528 + ... + 75034815.

Almost surely, 2^21609985392 is an apocalyptic number.

It is an amenable number.

21609985392 is an abundant number, since it is smaller than the sum of its proper divisors (38867960240).

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

21609985392 is a wasteful number, since it uses less digits than its factorization.

21609985392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150069357 (or 150069348 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

It can be divided in two parts, 21609 and 985392, that added together give a palindrome (1007001).

The spelling of 21609985392 in words is "twenty-one billion, six hundred nine million, nine hundred eighty-five thousand, three hundred ninety-two".