666665722 has 8 divisors (see below), whose sum is σ = 1023254496. Its totient is φ = 325580892.

The previous prime is 666665689. The next prime is 666665723. The reversal of 666665722 is 227566666.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (666665723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3875878 + ... + 3876049.

It is an arithmetic number, because the mean of its divisors is an integer number (127906812).

Almost surely, 2^666665722 is an apocalyptic number.

666665722 is a deficient number, since it is larger than the sum of its proper divisors (356588774).

666665722 is a wasteful number, since it uses less digits than its factorization.

666665722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7751972.

The product of its digits is 1088640, while the sum is 46.

The square root of 666665722 is about 25819.8706813183. The cubic root of 666665722 is about 873.5800521149.

The spelling of 666665722 in words is "six hundred sixty-six million, six hundred sixty-five thousand, seven hundred twenty-two".