1979187779 has 4 divisors (see below), whose sum is σ = 1993426680. Its totient is φ = 1964948880.

The previous prime is 1979187739. The next prime is 1979187799. The reversal of 1979187779 is 9777819791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1979187779 - 2¹² = 1979183683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1979187739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7119242 + ... + 7119519.

It is an arithmetic number, because the mean of its divisors is an integer number (498356670).

Almost surely, 2^1979187779 is an apocalyptic number.

1979187779 is a deficient number, since it is larger than the sum of its proper divisors (14238901).

1979187779 is a wasteful number, since it uses less digits than its factorization.

1979187779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14238900.

The product of its digits is 14002632, while the sum is 65.

The square root of 1979187779 is about 44488.0633316399. The cubic root of 1979187779 is about 1255.5355098394.

The spelling of 1979187779 in words is "one billion, nine hundred seventy-nine million, one hundred eighty-seven thousand, seven hundred seventy-nine".