20185808499 has 8 divisors (see below), whose sum is σ = 29904901520. Its totient is φ = 13457205648.

The previous prime is 20185808497. The next prime is 20185808509. The reversal of 20185808499 is 99480858102.

20185808499 is a `hidden beast` number, since 2 + 0 + 18 + 580 + 8 + 49 + 9 = 666.

It is not a de Polignac number, because 20185808499 - 2¹ = 20185808497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20185808491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 373811242 + ... + 373811295.

It is an arithmetic number, because the mean of its divisors is an integer number (3738112690).

Almost surely, 2^20185808499 is an apocalyptic number.

20185808499 is a deficient number, since it is larger than the sum of its proper divisors (9719093021).

20185808499 is an equidigital number, since it uses as much as digits as its factorization.

20185808499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747622546 (or 747622540 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 54.

The spelling of 20185808499 in words is "twenty billion, one hundred eighty-five million, eight hundred eight thousand, four hundred ninety-nine".