66190871 has 4 divisors (see below), whose sum is σ = 66232200. Its totient is φ = 66149544.

The previous prime is 66190867. The next prime is 66190879. The reversal of 66190871 is 17809166.

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

It is a cyclic number.

It is not a de Polignac number, because 66190871 - 2² = 66190867 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66190879) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18161 + ... + 21498.

It is an arithmetic number, because the mean of its divisors is an integer number (16558050).

Almost surely, 2^66190871 is an apocalyptic number.

66190871 is a deficient number, since it is larger than the sum of its proper divisors (41329).

66190871 is a wasteful number, since it uses less digits than its factorization.

66190871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41328.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 66190871 is about 8135.7772216304. Note that the first 3 decimals coincide. The cubic root of 66190871 is about 404.5132006145.

The spelling of 66190871 in words is "sixty-six million, one hundred ninety thousand, eight hundred seventy-one".