172144981 has 2 divisors, whose sum is σ = 172144982. Its totient is φ = 172144980.

The previous prime is 172144969. The next prime is 172145069. The reversal of 172144981 is 189441271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104346225 + 67798756 = 10215^2 + 8234^2 .

It is a cyclic number.

It is not a de Polignac number, because 172144981 - 2⁷ = 172144853 is a prime.

It is a super-2 number, since 2×172144981² = 59267788966980722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 172144981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172144961) 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 as a sum of consecutive naturals, namely, 86072490 + 86072491.

It is an arithmetic number, because the mean of its divisors is an integer number (86072491).

Almost surely, 2^172144981 is an apocalyptic number.

It is an amenable number.

172144981 is a deficient number, since it is larger than the sum of its proper divisors (1).

172144981 is an equidigital number, since it uses as much as digits as its factorization.

172144981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 37.

The square root of 172144981 is about 13120.4032331327. The cubic root of 172144981 is about 556.2859890699.

The spelling of 172144981 in words is "one hundred seventy-two million, one hundred forty-four thousand, nine hundred eighty-one".