666738718 has 4 divisors (see below), whose sum is σ = 1000108080. Its totient is φ = 333369358.

The previous prime is 666738647. The next prime is 666738719. The reversal of 666738718 is 817837666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666738719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166684678 + ... + 166684681.

It is an arithmetic number, because the mean of its divisors is an integer number (250027020).

Almost surely, 2^666738718 is an apocalyptic number.

666738718 is a deficient number, since it is larger than the sum of its proper divisors (333369362).

666738718 is a wasteful number, since it uses less digits than its factorization.

666738718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333369361.

The product of its digits is 2032128, while the sum is 52.

The square root of 666738718 is about 25821.2842050894. The cubic root of 666738718 is about 873.6119349212.

The spelling of 666738718 in words is "six hundred sixty-six million, seven hundred thirty-eight thousand, seven hundred eighteen".