168903981 has 16 divisors (see below), whose sum is σ = 250472320. Its totient is φ = 112492800.

The previous prime is 168903979. The next prime is 168903989. The reversal of 168903981 is 189309861.

It is not a de Polignac number, because 168903981 - 2¹ = 168903979 is a prime.

It is a super-2 number, since 2×168903981² = 57057109595296722, 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 (168903989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32781 + ... + 37581.

It is an arithmetic number, because the mean of its divisors is an integer number (15654520).

Almost surely, 2^168903981 is an apocalyptic number.

It is an amenable number.

168903981 is a deficient number, since it is larger than the sum of its proper divisors (81568339).

168903981 is a wasteful number, since it uses less digits than its factorization.

168903981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6113 (or 6107 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 168903981 is about 12996.3064368304. The cubic root of 168903981 is about 552.7727539518.

The spelling of 168903981 in words is "one hundred sixty-eight million, nine hundred three thousand, nine hundred eighty-one".