2156632321 has 8 divisors (see below), whose sum is σ = 2162751624. Its totient is φ = 2150522880.

The previous prime is 2156632301. The next prime is 2156632333. The reversal of 2156632321 is 1232366512.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1755191025 + 401441296 = 41895^2 + 20036^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2156632321 - 2⁷ = 2156632193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2156632301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 660525 + ... + 663781.

It is an arithmetic number, because the mean of its divisors is an integer number (270343953).

Almost surely, 2^2156632321 is an apocalyptic number.

It is an amenable number.

2156632321 is a deficient number, since it is larger than the sum of its proper divisors (6119303).

2156632321 is a wasteful number, since it uses less digits than its factorization.

2156632321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4931.

The product of its digits is 12960, while the sum is 31.

The square root of 2156632321 is about 46439.5555641955. Note that the first 4 decimals coincide. The cubic root of 2156632321 is about 1291.9886641661.

Adding to 2156632321 its reverse (1232366512), we get a palindrome (3388998833).

The spelling of 2156632321 in words is "two billion, one hundred fifty-six million, six hundred thirty-two thousand, three hundred twenty-one".