1990191 has 8 divisors (see below), whose sum is σ = 3032704. Its totient is φ = 1137240.

The previous prime is 1990189. The next prime is 1990211. The reversal of 1990191 is 1910991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1990191 - 2¹ = 1990189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47365 + ... + 47406.

It is an arithmetic number, because the mean of its divisors is an integer number (379088).

2^1990191 is an apocalyptic number.

1990191 is a deficient number, since it is larger than the sum of its proper divisors (1042513).

1990191 is an equidigital number, since it uses as much as digits as its factorization.

1990191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94781.

The product of its (nonzero) digits is 729, while the sum is 30.

The square root of 1990191 is about 1410.7412944973. The cubic root of 1990191 is about 125.7857912394.

The spelling of 1990191 in words is "one million, nine hundred ninety thousand, one hundred ninety-one".