166400478 has 24 divisors (see below), whose sum is σ = 361490688. Its totient is φ = 55319712.

The previous prime is 166400459. The next prime is 166400491. The reversal of 166400478 is 874004661.

166400478 is a `hidden beast` number, since 1 + 6 + 640 + 0 + 4 + 7 + 8 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5175 + ... + 18962.

It is an arithmetic number, because the mean of its divisors is an integer number (15062112).

Almost surely, 2^166400478 is an apocalyptic number.

166400478 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

166400478 is an abundant number, since it is smaller than the sum of its proper divisors (195090210).

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

166400478 is a wasteful number, since it uses less digits than its factorization.

166400478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24528 (or 24525 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 166400478 is about 12899.6309249529. The cubic root of 166400478 is about 550.0280734982.

The spelling of 166400478 in words is "one hundred sixty-six million, four hundred thousand, four hundred seventy-eight".