168865381 has 4 divisors (see below), whose sum is σ = 168898252. Its totient is φ = 168832512.

The previous prime is 168865357. The next prime is 168865387. The reversal of 168865381 is 183568861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 147622500 + 21242881 = 12150^2 + 4609^2 .

It is a cyclic number.

It is not a de Polignac number, because 168865381 - 2⁵ = 168865349 is a prime.

It is a super-2 number, since 2×168865381² = 57031033800550322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168865387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6876 + ... + 19621.

It is an arithmetic number, because the mean of its divisors is an integer number (42224563).

Almost surely, 2^168865381 is an apocalyptic number.

It is an amenable number.

168865381 is a deficient number, since it is larger than the sum of its proper divisors (32871).

168865381 is an equidigital number, since it uses as much as digits as its factorization.

168865381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32870.

The product of its digits is 276480, while the sum is 46.

The square root of 168865381 is about 12994.8213146622. The cubic root of 168865381 is about 552.7306419506.

The spelling of 168865381 in words is "one hundred sixty-eight million, eight hundred sixty-five thousand, three hundred eighty-one".