2781157779 has 6 divisors (see below), whose sum is σ = 4017227916. Its totient is φ = 1854105180.

The previous prime is 2781157763. The next prime is 2781157807. The reversal of 2781157779 is 9777511872.

It is not a de Polignac number, because 2781157779 - 2⁴ = 2781157763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2781157579) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 154508757 + ... + 154508774.

It is an arithmetic number, because the mean of its divisors is an integer number (669537986).

Almost surely, 2^2781157779 is an apocalyptic number.

2781157779 is a deficient number, since it is larger than the sum of its proper divisors (1236070137).

2781157779 is a wasteful number, since it uses less digits than its factorization.

2781157779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309017537 (or 309017534 counting only the distinct ones).

The product of its digits is 1728720, while the sum is 54.

The square root of 2781157779 is about 52736.6834281414. The cubic root of 2781157779 is about 1406.2910384231.

The spelling of 2781157779 in words is "two billion, seven hundred eighty-one million, one hundred fifty-seven thousand, seven hundred seventy-nine".