1329779891 has 16 divisors (see below), whose sum is σ = 1565948160. Its totient is φ = 1116450720.

The previous prime is 1329779879. The next prime is 1329779909. The reversal of 1329779891 is 1989779231.

It is a de Polignac number, because none of the positive numbers 2^k-1329779891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1329779291) 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, 83285 + ... + 97958.

It is an arithmetic number, because the mean of its divisors is an integer number (97871760).

Almost surely, 2^1329779891 is an apocalyptic number.

1329779891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1329779891 is a deficient number, since it is larger than the sum of its proper divisors (236168269).

1329779891 is a wasteful number, since it uses less digits than its factorization.

1329779891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181306.

The product of its digits is 1714608, while the sum is 56.

The square root of 1329779891 is about 36466.1471916077. The cubic root of 1329779891 is about 1099.6637790609.

The spelling of 1329779891 in words is "one billion, three hundred twenty-nine million, seven hundred seventy-nine thousand, eight hundred ninety-one".