172681 has 2 divisors, whose sum is σ = 172682. Its totient is φ = 172680.

The previous prime is 172673. The next prime is 172687. The reversal of 172681 is 186271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126025 + 46656 = 355^2 + 216^2 .

It is an emirp because it is prime and its reverse (186271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172681 - 2³ = 172673 is a prime.

It is a super-2 number, since 2×172681² = 59637455522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (172687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86340 + 86341.

It is an arithmetic number, because the mean of its divisors is an integer number (86341).

2¹⁷²⁶⁸¹ is an apocalyptic number.

It is an amenable number.

172681 is a deficient number, since it is larger than the sum of its proper divisors (1).

172681 is an equidigital number, since it uses as much as digits as its factorization.

172681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 25.

The square root of 172681 is about 415.5490344111. The cubic root of 172681 is about 55.6862772091.

The spelling of 172681 in words is "one hundred seventy-two thousand, six hundred eighty-one".