66665506 has 8 divisors (see below), whose sum is σ = 100039680. Its totient is φ = 33318948.

The previous prime is 66665479. The next prime is 66665513. The reversal of 66665506 is 60556666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 895 + ... + 11581.

It is an arithmetic number, because the mean of its divisors is an integer number (12504960).

Almost surely, 2^66665506 is an apocalyptic number.

66665506 is a deficient number, since it is larger than the sum of its proper divisors (33374174).

66665506 is a wasteful number, since it uses less digits than its factorization.

66665506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13808.

The product of its (nonzero) digits is 194400, while the sum is 40.

The square root of 66665506 is about 8164.8947329405. The cubic root of 66665506 is about 405.4777798882.

The spelling of 66665506 in words is "sixty-six million, six hundred sixty-five thousand, five hundred six".