20188131 has 4 divisors (see below), whose sum is σ = 26917512. Its totient is φ = 13458752.

The previous prime is 20188111. The next prime is 20188141. The reversal of 20188131 is 13188102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20188131 - 2⁶ = 20188067 is a prime.

It is a super-2 number, since 2×20188131² = 815121266546322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20188111) 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, 3364686 + ... + 3364691.

It is an arithmetic number, because the mean of its divisors is an integer number (6729378).

Almost surely, 2^20188131 is an apocalyptic number.

20188131 is a deficient number, since it is larger than the sum of its proper divisors (6729381).

20188131 is an equidigital number, since it uses as much as digits as its factorization.

20188131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6729380.

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 20188131 is about 4493.1204079125. The cubic root of 20188131 is about 272.2902170163.

The spelling of 20188131 in words is "twenty million, one hundred eighty-eight thousand, one hundred thirty-one".