667071217 has 4 divisors (see below), whose sum is σ = 667224180. Its totient is φ = 666918256.

The previous prime is 667071203. The next prime is 667071241. The reversal of 667071217 is 712170766.

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

It can be written as a sum of positive squares in 2 ways, for example, as 496220176 + 170851041 = 22276^2 + 13071^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667071217 is a prime.

It is a super-2 number, since 2×667071217² = 889968017099722178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667071917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69742 + ... + 78727.

It is an arithmetic number, because the mean of its divisors is an integer number (166806045).

Almost surely, 2^667071217 is an apocalyptic number.

It is an amenable number.

667071217 is a deficient number, since it is larger than the sum of its proper divisors (152963).

667071217 is a wasteful number, since it uses less digits than its factorization.

667071217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152962.

The product of its (nonzero) digits is 24696, while the sum is 37.

The square root of 667071217 is about 25827.7218701147. The cubic root of 667071217 is about 873.7571326397.

The spelling of 667071217 in words is "six hundred sixty-seven million, seventy-one thousand, two hundred seventeen".