166215438 has 24 divisors (see below), whose sum is σ = 361179000. Its totient is φ = 55244304.

The previous prime is 166215437. The next prime is 166215451. The reversal of 166215438 is 834512661.

It is a happy number.

166215438 is a `hidden beast` number, since 1 + 6 + 6 + 215 + 438 = 666.

166215438 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166215437) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6948 + ... + 19511.

It is an arithmetic number, because the mean of its divisors is an integer number (15049125).

Almost surely, 2^166215438 is an apocalyptic number.

166215438 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

166215438 is an abundant number, since it is smaller than the sum of its proper divisors (194963562).

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

166215438 is a wasteful number, since it uses less digits than its factorization.

166215438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26816 (or 26813 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 166215438 is about 12892.4566316897. The cubic root of 166215438 is about 549.8241178661.

The spelling of 166215438 in words is "one hundred sixty-six million, two hundred fifteen thousand, four hundred thirty-eight".