20185808 has 20 divisors (see below), whose sum is σ = 39270180. Its totient is φ = 10051584.

The previous prime is 20185801. The next prime is 20185859. The reversal of 20185808 is 80858102.

It can be written as a sum of positive squares in 2 ways, for example, as 19963024 + 222784 = 4468^2 + 472^2 .

It is a super-2 number, since 2×20185808² = 814933689225728, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20185801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1658 + ... + 6566.

It is an arithmetic number, because the mean of its divisors is an integer number (1963509).

Almost surely, 2^20185808 is an apocalyptic number.

It is an amenable number.

20185808 is a deficient number, since it is larger than the sum of its proper divisors (19084372).

20185808 is a wasteful number, since it uses less digits than its factorization.

20185808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5174 (or 5168 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 32.

The square root of 20185808 is about 4492.8618941606. The cubic root of 20185808 is about 272.2797726875.

The spelling of 20185808 in words is "twenty million, one hundred eighty-five thousand, eight hundred eight".