2155777986 has 16 divisors (see below), whose sum is σ = 4312512000. Its totient is φ = 718433328.

The previous prime is 2155777963. The next prime is 2155777993. The reversal of 2155777986 is 6897775512.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8641 + ... + 66228.

It is an arithmetic number, because the mean of its divisors is an integer number (269532000).

Almost surely, 2^2155777986 is an apocalyptic number.

2155777986 is an abundant number, since it is smaller than the sum of its proper divisors (2156734014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2155777986 is a wasteful number, since it uses less digits than its factorization.

2155777986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79673.

The product of its digits is 7408800, while the sum is 57.

The square root of 2155777986 is about 46430.3562984391. The cubic root of 2155777986 is about 1291.8180375044.

The spelling of 2155777986 in words is "two billion, one hundred fifty-five million, seven hundred seventy-seven thousand, nine hundred eighty-six".