20186931609 has 48 divisors (see below), whose sum is σ = 31810506000. Its totient is φ = 12261777408.

The previous prime is 20186931607. The next prime is 20186931613. The reversal of 20186931609 is 90613968102.

It is a happy number.

20186931609 is a `hidden beast` number, since 2 + 0 + 1 + 8 + 6 + 9 + 31 + 609 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 1701810009 + 18485121600 = 41253^2 + 135960^2 .

It is not a de Polignac number, because 20186931609 - 2¹ = 20186931607 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20186931607) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4639567 + ... + 4643915.

It is an arithmetic number, because the mean of its divisors is an integer number (662718875).

Almost surely, 2^20186931609 is an apocalyptic number.

It is an amenable number.

20186931609 is a deficient number, since it is larger than the sum of its proper divisors (11623574391).

20186931609 is a wasteful number, since it uses less digits than its factorization.

20186931609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4874 (or 4871 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The spelling of 20186931609 in words is "twenty billion, one hundred eighty-six million, nine hundred thirty-one thousand, six hundred nine".