168688631 has 4 divisors (see below), whose sum is σ = 177567000. Its totient is φ = 159810264.

The previous prime is 168688627. The next prime is 168688643. The reversal of 168688631 is 136886861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136886861 = 181 ⋅756281.

It is a cyclic number.

It is not a de Polignac number, because 168688631 - 2² = 168688627 is a prime.

It is a super-2 number, since 2×168688631² = 56911708457308322, 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 (168688651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4439156 + ... + 4439193.

It is an arithmetic number, because the mean of its divisors is an integer number (44391750).

Almost surely, 2^168688631 is an apocalyptic number.

168688631 is a deficient number, since it is larger than the sum of its proper divisors (8878369).

168688631 is an equidigital number, since it uses as much as digits as its factorization.

168688631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8878368.

The product of its digits is 331776, while the sum is 47.

The square root of 168688631 is about 12988.0187480616. The cubic root of 168688631 is about 552.5377284283.

The spelling of 168688631 in words is "one hundred sixty-eight million, six hundred eighty-eight thousand, six hundred thirty-one".