155668 has 6 divisors (see below), whose sum is σ = 272426. Its totient is φ = 77832.

The previous prime is 155663. The next prime is 155671. The reversal of 155668 is 866551.

It can be written as a sum of positive squares in only one way, i.e., 103684 + 51984 = 322^2 + 228^2 .

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155663) by changing a digit.

155668 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 (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19455 + ... + 19462.

2¹⁵⁵⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

155668 is a deficient number, since it is larger than the sum of its proper divisors (116758).

155668 is a wasteful number, since it uses less digits than its factorization.

155668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38921 (or 38919 counting only the distinct ones).

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

The square root of 155668 is about 394.5478424729. The cubic root of 155668 is about 53.7939103954.

The spelling of 155668 in words is "one hundred fifty-five thousand, six hundred sixty-eight".