66666699 has 16 divisors (see below), whose sum is σ = 107744640. Its totient is φ = 40403880.

The previous prime is 66666683. The next prime is 66666713. The reversal of 66666699 is 99666666.

It is not a de Polignac number, because 66666699 - 2⁴ = 66666683 is a prime.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66666629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111937 + ... + 112530.

It is an arithmetic number, because the mean of its divisors is an integer number (6734040).

Almost surely, 2^66666699 is an apocalyptic number.

66666699 is a deficient number, since it is larger than the sum of its proper divisors (41077941).

66666699 is a wasteful number, since it uses less digits than its factorization.

66666699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224487 (or 224481 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 54.

The square root of 66666699 is about 8164.9677892812. The cubic root of 66666699 is about 405.4801985908.

The spelling of 66666699 in words is "sixty-six million, six hundred sixty-six thousand, six hundred ninety-nine".