66664994 has 16 divisors (see below), whose sum is σ = 113832000. Its totient is φ = 28984560.

The previous prime is 66664993. The next prime is 66665021. The reversal of 66664994 is 49946666.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (66664991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65369 + ... + 66380.

It is an arithmetic number, because the mean of its divisors is an integer number (7114500).

Almost surely, 2^66664994 is an apocalyptic number.

66664994 is a deficient number, since it is larger than the sum of its proper divisors (47167006).

66664994 is a wasteful number, since it uses less digits than its factorization.

66664994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131785.

The product of its digits is 1679616, while the sum is 50.

The square root of 66664994 is about 8164.8633791387. The cubic root of 66664994 is about 405.4767418444.

The spelling of 66664994 in words is "sixty-six million, six hundred sixty-four thousand, nine hundred ninety-four".