2156623145 has 16 divisors (see below), whose sum is σ = 2755338768. Its totient is φ = 1614827520.

The previous prime is 2156623141. The next prime is 2156623187. The reversal of 2156623145 is 5413266512.

It can be written as a sum of positive squares in 8 ways, for example, as 361152016 + 1795471129 = 19004^2 + 42373^2 .

It is not a de Polignac number, because 2156623145 - 2² = 2156623141 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2156623141) by changing a digit.

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, 54704 + ... + 85473.

It is an arithmetic number, because the mean of its divisors is an integer number (172208673).

Almost surely, 2^2156623145 is an apocalyptic number.

It is an amenable number.

2156623145 is a deficient number, since it is larger than the sum of its proper divisors (598715623).

2156623145 is a wasteful number, since it uses less digits than its factorization.

2156623145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140380.

The product of its digits is 43200, while the sum is 35.

The square root of 2156623145 is about 46439.4567690019. The cubic root of 2156623145 is about 1291.9868317869.

Adding to 2156623145 its reverse (5413266512), we get a palindrome (7569889657).

The spelling of 2156623145 in words is "two billion, one hundred fifty-six million, six hundred twenty-three thousand, one hundred forty-five".