21609317140 has 24 divisors (see below), whose sum is σ = 45953994240. Its totient is φ = 8534311968.

The previous prime is 21609317131. The next prime is 21609317159. The reversal of 21609317140 is 4171390612.

It is a junction number, because it is equal to n+sod(n) for n = 21609317096 and 21609317105.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6836812 + ... + 6839971.

It is an arithmetic number, because the mean of its divisors is an integer number (1914749760).

Almost surely, 2^21609317140 is an apocalyptic number.

21609317140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21609317140 is an abundant number, since it is smaller than the sum of its proper divisors (24344677100).

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

21609317140 is a wasteful number, since it uses less digits than its factorization.

21609317140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13676871 (or 13676869 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 34.

The spelling of 21609317140 in words is "twenty-one billion, six hundred nine million, three hundred seventeen thousand, one hundred forty".