156691 has 2 divisors, whose sum is σ = 156692. Its totient is φ = 156690.

The previous prime is 156683. The next prime is 156703. The reversal of 156691 is 196651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 156691 - 2³ = 156683 is a prime.

It is not a weakly prime, because it can be changed into another prime (156601) 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, 78345 + 78346.

It is an arithmetic number, because the mean of its divisors is an integer number (78346).

2¹⁵⁶⁶⁹¹ is an apocalyptic number.

156691 is a deficient number, since it is larger than the sum of its proper divisors (1).

156691 is an equidigital number, since it uses as much as digits as its factorization.

156691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 28.

The square root of 156691 is about 395.8421402529. The cubic root of 156691 is about 53.9114919568.

The spelling of 156691 in words is "one hundred fifty-six thousand, six hundred ninety-one".