156865 has 8 divisors (see below), whose sum is σ = 190440. Its totient is φ = 124032.

The previous prime is 156841. The next prime is 156887. The reversal of 156865 is 568651.

156865 is an esthetic number in base 6, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 4 ways, for example, as 53824 + 103041 = 232^2 + 321^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 156865 - 2⁵ = 156833 is a prime.

It is a plaindrome in base 7.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 571 + ... + 799.

It is an arithmetic number, because the mean of its divisors is an integer number (23805).

2¹⁵⁶⁸⁶⁵ is an apocalyptic number.

156865 is the 229-th octagonal number.

It is an amenable number.

156865 is a deficient number, since it is larger than the sum of its proper divisors (33575).

156865 is a wasteful number, since it uses less digits than its factorization.

156865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371.

The product of its digits is 7200, while the sum is 31.

The square root of 156865 is about 396.0618638546. The cubic root of 156865 is about 53.9314401978.

It can be divided in two parts, 156 and 865, that multiplied together give a triangular number (134940 = T₅₁₉).

The spelling of 156865 in words is "one hundred fifty-six thousand, eight hundred sixty-five".