1977792139 has 4 divisors (see below), whose sum is σ = 2004885256. Its totient is φ = 1950699024.

The previous prime is 1977792127. The next prime is 1977792151. The reversal of 1977792139 is 9312977791.

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

It is an interprime number because it is at equal distance from previous prime (1977792127) and next prime (1977792151).

It is a cyclic number.

It is not a de Polignac number, because 1977792139 - 2⁵ = 1977792107 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1977792139.

It is not an unprimeable number, because it can be changed into a prime (1977792109) 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, 13546449 + ... + 13546594.

It is an arithmetic number, because the mean of its divisors is an integer number (501221314).

Almost surely, 2^1977792139 is an apocalyptic number.

1977792139 is a deficient number, since it is larger than the sum of its proper divisors (27093117).

1977792139 is an equidigital number, since it uses as much as digits as its factorization.

1977792139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27093116.

The product of its digits is 1500282, while the sum is 55.

The square root of 1977792139 is about 44472.3750096619. The cubic root of 1977792139 is about 1255.2403234948.

The spelling of 1977792139 in words is "one billion, nine hundred seventy-seven million, seven hundred ninety-two thousand, one hundred thirty-nine".