168421881 has 4 divisors (see below), whose sum is σ = 224562512. Its totient is φ = 112281252.

The previous prime is 168421837. The next prime is 168421889. The reversal of 168421881 is 188124861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 168421881 - 2²¹ = 166324729 is a prime.

It is a super-2 number, since 2×168421881² = 56731859999156322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168421889) 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, 28070311 + ... + 28070316.

It is an arithmetic number, because the mean of its divisors is an integer number (56140628).

Almost surely, 2^168421881 is an apocalyptic number.

It is an amenable number.

168421881 is a deficient number, since it is larger than the sum of its proper divisors (56140631).

168421881 is an equidigital number, since it uses as much as digits as its factorization.

168421881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56140630.

The product of its digits is 24576, while the sum is 39.

The square root of 168421881 is about 12977.7456054586. The cubic root of 168421881 is about 552.2463292268.

The spelling of 168421881 in words is "one hundred sixty-eight million, four hundred twenty-one thousand, eight hundred eighty-one".