166421388 has 48 divisors (see below), whose sum is σ = 444899840. Its totient is φ = 47430144.

The previous prime is 166421383. The next prime is 166421417. The reversal of 166421388 is 883124661.

It is not an unprimeable number, because it can be changed into a prime (166421383) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34620 + ... + 39132.

Almost surely, 2^166421388 is an apocalyptic number.

It is an amenable number.

166421388 is an abundant number, since it is smaller than the sum of its proper divisors (278478452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166421388 is a wasteful number, since it uses less digits than its factorization.

166421388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4966 (or 4964 counting only the distinct ones).

The product of its digits is 55296, while the sum is 39.

The square root of 166421388 is about 12900.4413877976. The cubic root of 166421388 is about 550.0511115035.

The spelling of 166421388 in words is "one hundred sixty-six million, four hundred twenty-one thousand, three hundred eighty-eight".