20188331 has 2 divisors, whose sum is σ = 20188332. Its totient is φ = 20188330.

The previous prime is 20188327. The next prime is 20188361. The reversal of 20188331 is 13388102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20188331 - 2² = 20188327 is a prime.

It is a super-2 number, since 2×20188331² = 815137417131122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20188331.

It is not a weakly prime, because it can be changed into another prime (20188361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10094165 + 10094166.

It is an arithmetic number, because the mean of its divisors is an integer number (10094166).

Almost surely, 2^20188331 is an apocalyptic number.

20188331 is a deficient number, since it is larger than the sum of its proper divisors (1).

20188331 is an equidigital number, since it uses as much as digits as its factorization.

20188331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 20188331 is about 4493.1426641049. The cubic root of 20188331 is about 272.2911161893.

The spelling of 20188331 in words is "twenty million, one hundred eighty-eight thousand, three hundred thirty-one".