66909263 has 4 divisors (see below), whose sum is σ = 70845120. Its totient is φ = 62973408.

The previous prime is 66909239. The next prime is 66909281. The reversal of 66909263 is 36290966.

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 66909263 - 2²⁰ = 65860687 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66909263.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66909223) 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, 1967903 + ... + 1967936.

It is an arithmetic number, because the mean of its divisors is an integer number (17711280).

Almost surely, 2^66909263 is an apocalyptic number.

66909263 is a deficient number, since it is larger than the sum of its proper divisors (3935857).

66909263 is a wasteful number, since it uses less digits than its factorization.

66909263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3935856.

The product of its (nonzero) digits is 104976, while the sum is 41.

The square root of 66909263 is about 8179.8082495863. The cubic root of 66909263 is about 405.9713776161.

The spelling of 66909263 in words is "sixty-six million, nine hundred nine thousand, two hundred sixty-three".