1900091 has 4 divisors (see below), whose sum is σ = 1911912. Its totient is φ = 1888272.

The previous prime is 1900079. The next prime is 1900111.

1900091 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1900091 is a prime.

It is a super-2 number, since 2×1900091² = 7220691616562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1900291) 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, 5666 + ... + 5991.

It is an arithmetic number, because the mean of its divisors is an integer number (477978).

2^1900091 is an apocalyptic number.

1900091 is a deficient number, since it is larger than the sum of its proper divisors (11821).

1900091 is a wasteful number, since it uses less digits than its factorization.

1900091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11820.

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 1900091 is about 1378.4378839832. The cubic root of 1900091 is about 123.8582102853.

It can be divided in two parts, 19000 and 91, that added together give a palindrome (19091).

The spelling of 1900091 in words is "one million, nine hundred thousand, ninety-one".