66266993 has 4 divisors (see below), whose sum is σ = 71364468. Its totient is φ = 61169520.

The previous prime is 66266957. The next prime is 66267049. The reversal of 66266993 is 39966266.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13965169 + 52301824 = 3737^2 + 7232^2 .

It is a cyclic number.

It is not a de Polignac number, because 66266993 - 2²⁴ = 49489777 is a prime.

It is a super-2 number, since 2×66266993² = 8782628722524098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66266393) 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, 2548718 + ... + 2548743.

It is an arithmetic number, because the mean of its divisors is an integer number (17841117).

Almost surely, 2^66266993 is an apocalyptic number.

It is an amenable number.

66266993 is a deficient number, since it is larger than the sum of its proper divisors (5097475).

66266993 is a wasteful number, since it uses less digits than its factorization.

66266993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5097474.

The product of its digits is 629856, while the sum is 47.

The square root of 66266993 is about 8140.4541028127. The cubic root of 66266993 is about 404.6682096906.

The spelling of 66266993 in words is "sixty-six million, two hundred sixty-six thousand, nine hundred ninety-three".