1990495839 has 16 divisors (see below), whose sum is σ = 2721739104. Its totient is φ = 1293196800.

The previous prime is 1990495799. The next prime is 1990495861. The reversal of 1990495839 is 9385940991.

It is not a de Polignac number, because 1990495839 - 2¹⁹ = 1989971551 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990490839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108729 + ... + 125709.

It is an arithmetic number, because the mean of its divisors is an integer number (170108694).

Almost surely, 2^1990495839 is an apocalyptic number.

1990495839 is a deficient number, since it is larger than the sum of its proper divisors (731243265).

1990495839 is a wasteful number, since it uses less digits than its factorization.

1990495839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17978.

The product of its (nonzero) digits is 3149280, while the sum is 57.

The square root of 1990495839 is about 44614.9732601063. The cubic root of 1990495839 is about 1257.9221314518.

The spelling of 1990495839 in words is "one billion, nine hundred ninety million, four hundred ninety-five thousand, eight hundred thirty-nine".