169681 has 2 divisors, whose sum is σ = 169682. Its totient is φ = 169680.

The previous prime is 169667. The next prime is 169691. The reversal of 169681 is 186961.

It is a happy number.

169681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144400 + 25281 = 380^2 + 159^2 .

It is a cyclic number.

It is not a de Polignac number, because 169681 - 2⁵ = 169649 is a prime.

It is a super-2 number, since 2×169681² = 57583283522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (169661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84840 + 84841.

It is an arithmetic number, because the mean of its divisors is an integer number (84841).

2¹⁶⁹⁶⁸¹ is an apocalyptic number.

It is an amenable number.

169681 is a deficient number, since it is larger than the sum of its proper divisors (1).

169681 is an equidigital number, since it uses as much as digits as its factorization.

169681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 31.

The square root of 169681 is about 411.9235365939. The cubic root of 169681 is about 55.3619108524.

The spelling of 169681 in words is "one hundred sixty-nine thousand, six hundred eighty-one".