172320961 has 2 divisors, whose sum is σ = 172320962. Its totient is φ = 172320960.

The previous prime is 172320931. The next prime is 172320979. The reversal of 172320961 is 169023271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128958736 + 43362225 = 11356^2 + 6585^2 .

It is a cyclic number.

It is not a de Polignac number, because 172320961 - 2¹⁹ = 171796673 is a prime.

It is a Chen prime.

It is equal to p_9625630 and since 172320961 and 9625630 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (172320901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86160480 + 86160481.

It is an arithmetic number, because the mean of its divisors is an integer number (86160481).

Almost surely, 2^172320961 is an apocalyptic number.

It is an amenable number.

172320961 is a deficient number, since it is larger than the sum of its proper divisors (1).

172320961 is an equidigital number, since it uses as much as digits as its factorization.

172320961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 172320961 is about 13127.1078688339. The cubic root of 172320961 is about 556.4754841261.

The spelling of 172320961 in words is "one hundred seventy-two million, three hundred twenty thousand, nine hundred sixty-one".