172221281 has 2 divisors, whose sum is σ = 172221282. Its totient is φ = 172221280.

The previous prime is 172221241. The next prime is 172221299. The reversal of 172221281 is 182122271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171191056 + 1030225 = 13084^2 + 1015^2 .

It is a cyclic number.

It is not a de Polignac number, because 172221281 - 2²² = 168026977 is a prime.

It is a super-2 number, since 2×172221281² = 59320339258561922, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 172221281.

It is not a weakly prime, because it can be changed into another prime (172221241) 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, 86110640 + 86110641.

It is an arithmetic number, because the mean of its divisors is an integer number (86110641).

Almost surely, 2^172221281 is an apocalyptic number.

It is an amenable number.

172221281 is a deficient number, since it is larger than the sum of its proper divisors (1).

172221281 is an equidigital number, since it uses as much as digits as its factorization.

172221281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 896, while the sum is 26.

The square root of 172221281 is about 13123.3105960348. The cubic root of 172221281 is about 556.3681646704.

The spelling of 172221281 in words is "one hundred seventy-two million, two hundred twenty-one thousand, two hundred eighty-one".