20189431 has 2 divisors, whose sum is σ = 20189432. Its totient is φ = 20189430.

The previous prime is 20189399. The next prime is 20189437. The reversal of 20189431 is 13498102.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20189431 - 2⁵ = 20189399 is a prime.

It is a super-2 number, since 2×20189431² = 815226248207522, 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 20189431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20189437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10094715 + 10094716.

It is an arithmetic number, because the mean of its divisors is an integer number (10094716).

Almost surely, 2^20189431 is an apocalyptic number.

20189431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20189431 is an equidigital number, since it uses as much as digits as its factorization.

20189431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 20189431 is about 4493.2650711927. The cubic root of 20189431 is about 272.2960615343.

It can be divided in two parts, 2018 and 9431, that added together give a square (11449 = 107²).

The spelling of 20189431 in words is "twenty million, one hundred eighty-nine thousand, four hundred thirty-one".