1999265491 has 4 divisors (see below), whose sum is σ = 1999513192. Its totient is φ = 1999017792.

The previous prime is 1999265479. The next prime is 1999265503. The reversal of 1999265491 is 1945629991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1945629991 = 17 ⋅114448823.

It is an interprime number because it is at equal distance from previous prime (1999265479) and next prime (1999265503).

It is a cyclic number.

It is not a de Polignac number, because 1999265491 - 2²⁷ = 1865047763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1999265441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111321 + ... + 128026.

It is an arithmetic number, because the mean of its divisors is an integer number (499878298).

Almost surely, 2^1999265491 is an apocalyptic number.

1999265491 is a deficient number, since it is larger than the sum of its proper divisors (247701).

1999265491 is an equidigital number, since it uses as much as digits as its factorization.

1999265491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247700.

The product of its digits is 1574640, while the sum is 55.

The square root of 1999265491 is about 44713.1467356079. The cubic root of 1999265491 is about 1259.7667937845.

The spelling of 1999265491 in words is "one billion, nine hundred ninety-nine million, two hundred sixty-five thousand, four hundred ninety-one".