2156776505 has 16 divisors (see below), whose sum is σ = 2855203344. Its totient is φ = 1553848320.

The previous prime is 2156776463. The next prime is 2156776511. The reversal of 2156776505 is 5056776512.

It can be written as a sum of positive squares in 8 ways, for example, as 625150009 + 1531626496 = 25003^2 + 39136^2 .

It is not a de Polignac number, because 2156776505 - 2¹⁸ = 2156514361 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 401984 + ... + 407313.

It is an arithmetic number, because the mean of its divisors is an integer number (178450209).

Almost surely, 2^2156776505 is an apocalyptic number.

It is an amenable number.

2156776505 is a deficient number, since it is larger than the sum of its proper divisors (698426839).

2156776505 is a wasteful number, since it uses less digits than its factorization.

2156776505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809356.

The product of its (nonzero) digits is 441000, while the sum is 44.

The square root of 2156776505 is about 46441.1079217540. The cubic root of 2156776505 is about 1292.0174559604.

The spelling of 2156776505 in words is "two billion, one hundred fifty-six million, seven hundred seventy-six thousand, five hundred five".