666722289 has 8 divisors (see below), whose sum is σ = 890062432. Its totient is φ = 443931840.

The previous prime is 666722281. The next prime is 666722297. The reversal of 666722289 is 982227666.

It is an interprime number because it is at equal distance from previous prime (666722281) and next prime (666722297).

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

It is not a de Polignac number, because 666722289 - 2³ = 666722281 is a prime.

It is a super-2 number, since 2×666722289² = 889037221298799042, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (666722281) 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, 134584 + ... + 139449.

It is an arithmetic number, because the mean of its divisors is an integer number (111257804).

Almost surely, 2^666722289 is an apocalyptic number.

It is an amenable number.

666722289 is a deficient number, since it is larger than the sum of its proper divisors (223340143).

666722289 is a wasteful number, since it uses less digits than its factorization.

666722289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274847.

The product of its digits is 870912, while the sum is 48.

The square root of 666722289 is about 25820.9660741034. The cubic root of 666722289 is about 873.6047593526.

The spelling of 666722289 in words is "six hundred sixty-six million, seven hundred twenty-two thousand, two hundred eighty-nine".