1900189891 has 2 divisors, whose sum is σ = 1900189892. Its totient is φ = 1900189890.

The previous prime is 1900189859. The next prime is 1900189901. The reversal of 1900189891 is 1989810091.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1900189891 - 2⁵ = 1900189859 is a prime.

It is a super-2 number, since 2×1900189891² = 7221443243717183762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1900189801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950094945 + 950094946.

It is an arithmetic number, because the mean of its divisors is an integer number (950094946).

Almost surely, 2^1900189891 is an apocalyptic number.

1900189891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1900189891 is an equidigital number, since it uses as much as digits as its factorization.

1900189891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 46.

The square root of 1900189891 is about 43591.1675801417. The cubic root of 1900189891 is about 1238.6035899818.

The spelling of 1900189891 in words is "one billion, nine hundred million, one hundred eighty-nine thousand, eight hundred ninety-one".