2172630181 has 2 divisors, whose sum is σ = 2172630182. Its totient is φ = 2172630180.

The previous prime is 2172630167. The next prime is 2172630197. The reversal of 2172630181 is 1810362712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2002562500 + 170067681 = 44750^2 + 13041^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2172630181 is a prime.

It is a super-2 number, since 2×2172630181² = 9440643806784185522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2172630281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1086315090 + 1086315091.

It is an arithmetic number, because the mean of its divisors is an integer number (1086315091).

Almost surely, 2^2172630181 is an apocalyptic number.

It is an amenable number.

2172630181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2172630181 is an equidigital number, since it uses as much as digits as its factorization.

2172630181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 2172630181 is about 46611.4812143961. The cubic root of 2172630181 is about 1295.1754468793.

Adding to 2172630181 its reverse (1810362712), we get a palindrome (3982992893).

The spelling of 2172630181 in words is "two billion, one hundred seventy-two million, six hundred thirty thousand, one hundred eighty-one".