155978 has 8 divisors (see below), whose sum is σ = 235872. Its totient is φ = 77356.

The previous prime is 155921. The next prime is 156007. The reversal of 155978 is 879551.

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

It is a Curzon number.

It is a nialpdrome in base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 155978.

It is an unprimeable number.

155978 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 3 ways as a sum of consecutive naturals, for example, 101 + ... + 567.

It is an arithmetic number, because the mean of its divisors is an integer number (29484).

2¹⁵⁵⁹⁷⁸ is an apocalyptic number.

155978 is a deficient number, since it is larger than the sum of its proper divisors (79894).

155978 is a wasteful number, since it uses less digits than its factorization.

155978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636.

The product of its digits is 12600, while the sum is 35.

The square root of 155978 is about 394.9405018481. The cubic root of 155978 is about 53.8295954319.

The spelling of 155978 in words is "one hundred fifty-five thousand, nine hundred seventy-eight".