20985681140 has 24 divisors (see below), whose sum is σ = 44099749512. Its totient is φ = 8388592640.

The previous prime is 20985681113. The next prime is 20985681169. The reversal of 20985681140 is 4118658902.

It can be written as a sum of positive squares in 4 ways, for example, as 2999824 + 20982681316 = 1732^2 + 144854^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20985681091 and 20985681100.

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, 324629 + ... + 383868.

It is an arithmetic number, because the mean of its divisors is an integer number (1837489563).

Almost surely, 2^20985681140 is an apocalyptic number.

20985681140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20985681140 is an abundant number, since it is smaller than the sum of its proper divisors (23114068372).

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

20985681140 is a wasteful number, since it uses less digits than its factorization.

20985681140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709987 (or 709985 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 20985681140 in words is "twenty billion, nine hundred eighty-five million, six hundred eighty-one thousand, one hundred forty".