2172155281 has 2 divisors, whose sum is σ = 2172155282. Its totient is φ = 2172155280.

The previous prime is 2172155239. The next prime is 2172155317. The reversal of 2172155281 is 1825512712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1302849025 + 869306256 = 36095^2 + 29484^2 .

It is a cyclic number.

It is not a de Polignac number, because 2172155281 - 2⁹ = 2172154769 is a prime.

It is a super-2 number, since 2×2172155281² = 9436517129552377922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2172155231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1086077640 + 1086077641.

It is an arithmetic number, because the mean of its divisors is an integer number (1086077641).

Almost surely, 2^2172155281 is an apocalyptic number.

It is an amenable number.

2172155281 is a deficient number, since it is larger than the sum of its proper divisors (1).

2172155281 is an equidigital number, since it uses as much as digits as its factorization.

2172155281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11200, while the sum is 34.

The square root of 2172155281 is about 46606.3866975332. The cubic root of 2172155281 is about 1295.0810722290.

Adding to 2172155281 its reverse (1825512712), we get a palindrome (3997667993).

The spelling of 2172155281 in words is "two billion, one hundred seventy-two million, one hundred fifty-five thousand, two hundred eighty-one".