66416165 has 4 divisors (see below), whose sum is σ = 79699404. Its totient is φ = 53132928.

The previous prime is 66416159. The next prime is 66416171. The reversal of 66416165 is 56161466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56161466 = 2 ⋅28080733.

It is an interprime number because it is at equal distance from previous prime (66416159) and next prime (66416171).

It can be written as a sum of positive squares in 2 ways, for example, as 48455521 + 17960644 = 6961^2 + 4238^2 .

It is a cyclic number.

It is not a de Polignac number, because 66416165 - 2⁴ = 66416149 is a prime.

It is a super-2 number, since 2×66416165² = 8822213946614450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent 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, 6641612 + ... + 6641621.

It is an arithmetic number, because the mean of its divisors is an integer number (19924851).

Almost surely, 2^66416165 is an apocalyptic number.

It is an amenable number.

66416165 is a deficient number, since it is larger than the sum of its proper divisors (13283239).

66416165 is a wasteful number, since it uses less digits than its factorization.

66416165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13283238.

The product of its digits is 25920, while the sum is 35.

The square root of 66416165 is about 8149.6113404260. The cubic root of 66416165 is about 404.9716283534.

The spelling of 66416165 in words is "sixty-six million, four hundred sixteen thousand, one hundred sixty-five".