20868185 has 16 divisors (see below), whose sum is σ = 27700176. Its totient is φ = 14992128.

The previous prime is 20868181. The next prime is 20868193. The reversal of 20868185 is 58186802.

It can be written as a sum of positive squares in 8 ways, for example, as 546121 + 20322064 = 739^2 + 4508^2 .

It is a cyclic number.

It is not a de Polignac number, because 20868185 - 2² = 20868181 is a prime.

It is a super-2 number, since 2×20868185² = 870962290388450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20868181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1934 + ... + 6743.

It is an arithmetic number, because the mean of its divisors is an integer number (1731261).

Almost surely, 2^20868185 is an apocalyptic number.

It is an amenable number.

20868185 is a deficient number, since it is larger than the sum of its proper divisors (6831991).

20868185 is a wasteful number, since it uses less digits than its factorization.

20868185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8732.

The product of its (nonzero) digits is 30720, while the sum is 38.

The square root of 20868185 is about 4568.1708593265. The cubic root of 20868185 is about 275.3139554839.

The spelling of 20868185 in words is "twenty million, eight hundred sixty-eight thousand, one hundred eighty-five".