166643915 has 4 divisors (see below), whose sum is σ = 199972704. Its totient is φ = 133315128.

The previous prime is 166643891. The next prime is 166643951. The reversal of 166643915 is 519346661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166643915 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16664387 + ... + 16664396.

It is an arithmetic number, because the mean of its divisors is an integer number (49993176).

Almost surely, 2^166643915 is an apocalyptic number.

166643915 is a deficient number, since it is larger than the sum of its proper divisors (33328789).

166643915 is an equidigital number, since it uses as much as digits as its factorization.

166643915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33328788.

The product of its digits is 116640, while the sum is 41.

The square root of 166643915 is about 12909.0632890229. The cubic root of 166643915 is about 550.2961655602.

The spelling of 166643915 in words is "one hundred sixty-six million, six hundred forty-three thousand, nine hundred fifteen".