666698617 has 32 divisors (see below), whose sum is σ = 769556480. Its totient is φ = 573168960.

The previous prime is 666698611. The next prime is 666698651. The reversal of 666698617 is 716896666.

It is not a de Polignac number, because 666698617 - 2¹⁵ = 666665849 is a prime.

It is a super-3 number, since 3×666698617³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666698611) 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 31 ways as a sum of consecutive naturals, for example, 1368748 + ... + 1369234.

It is an arithmetic number, because the mean of its divisors is an integer number (24048640).

Almost surely, 2^666698617 is an apocalyptic number.

It is an amenable number.

666698617 is a deficient number, since it is larger than the sum of its proper divisors (102857863).

666698617 is a wasteful number, since it uses less digits than its factorization.

666698617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653.

The product of its digits is 3919104, while the sum is 55.

The square root of 666698617 is about 25820.5076828478. The cubic root of 666698617 is about 873.5944201069.

The spelling of 666698617 in words is "six hundred sixty-six million, six hundred ninety-eight thousand, six hundred seventeen".