166978422 has 144 divisors (see below), whose sum is σ = 431645760. Its totient is φ = 48218976.

The previous prime is 166978397. The next prime is 166978423. The reversal of 166978422 is 224879661.

It is a happy number.

It is a super-2 number, since 2×166978422² = 55763586827220168, which contains 22 as substring.

Its product of digits (290304) is a multiple of the sum of its prime divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166978423) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1560493 + ... + 1560599.

It is an arithmetic number, because the mean of its divisors is an integer number (2997540).

Almost surely, 2^166978422 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166978422, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215822880).

166978422 is an abundant number, since it is smaller than the sum of its proper divisors (264667338).

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

166978422 is a wasteful number, since it uses less digits than its factorization.

166978422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 144 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 166978422 is about 12922.0130784642. The cubic root of 166978422 is about 550.6641255686.

The spelling of 166978422 in words is "one hundred sixty-six million, nine hundred seventy-eight thousand, four hundred twenty-two".