1999791 has 6 divisors (see below), whose sum is σ = 2888600. Its totient is φ = 1333188.

The previous prime is 1999771. The next prime is 1999799. The reversal of 1999791 is 1979991.

It is not a de Polignac number, because 1999791 - 2¹⁵ = 1967023 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 (1999799) 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 in 5 ways as a sum of consecutive naturals, for example, 111091 + ... + 111108.

2^1999791 is an apocalyptic number.

1999791 is a deficient number, since it is larger than the sum of its proper divisors (888809).

1999791 is a wasteful number, since it uses less digits than its factorization.

1999791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222205 (or 222202 counting only the distinct ones).

The product of its digits is 45927, while the sum is 45.

The square root of 1999791 is about 1414.1396677839. The cubic root of 1999791 is about 125.9877161116.

The spelling of 1999791 in words is "one million, nine hundred ninety-nine thousand, seven hundred ninety-one".