66492191 has 4 divisors (see below), whose sum is σ = 69991800. Its totient is φ = 62992584.

The previous prime is 66492163. The next prime is 66492193. The reversal of 66492191 is 19129466.

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-66492191 is a prime.

It is a super-2 number, since 2×66492191² = 8842422927960962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66492193) 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, 1749776 + ... + 1749813.

It is an arithmetic number, because the mean of its divisors is an integer number (17497950).

Almost surely, 2^66492191 is an apocalyptic number.

66492191 is a deficient number, since it is larger than the sum of its proper divisors (3499609).

66492191 is a wasteful number, since it uses less digits than its factorization.

66492191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3499608.

The product of its digits is 23328, while the sum is 38.

The square root of 66492191 is about 8154.2744005828. The cubic root of 66492191 is about 405.1260919179.

The spelling of 66492191 in words is "sixty-six million, four hundred ninety-two thousand, one hundred ninety-one".