155689 has 2 divisors, whose sum is σ = 155690. Its totient is φ = 155688.

The previous prime is 155671. The next prime is 155693. The reversal of 155689 is 986551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153664 + 2025 = 392^2 + 45^2 .

It is a cyclic number.

It is not a de Polignac number, because 155689 - 2⁵ = 155657 is a prime.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (155609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77844 + 77845.

It is an arithmetic number, because the mean of its divisors is an integer number (77845).

2¹⁵⁵⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

155689 is a deficient number, since it is larger than the sum of its proper divisors (1).

155689 is an equidigital number, since it uses as much as digits as its factorization.

155689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 34.

The square root of 155689 is about 394.5744543176. The cubic root of 155689 is about 53.7963292641.

The spelling of 155689 in words is "one hundred fifty-five thousand, six hundred eighty-nine".