668377609 has 9 divisors (see below), whose sum is σ = 677629389. Its totient is φ = 659251500.

The previous prime is 668377597. The next prime is 668377621. The reversal of 668377609 is 906773866.

The square root of 668377609 is 25853.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (668377597) and next prime (668377621).

It is not a de Polignac number, because 668377609 - 2⁷ = 668377481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668377009) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2662734 + ... + 2662984.

Almost surely, 2^668377609 is an apocalyptic number.

668377609 is the 25853-rd square number.

668377609 is the 12927-th centered octagonal number.

It is an amenable number.

668377609 is a deficient number, since it is larger than the sum of its proper divisors (9251780).

668377609 is an frugal number, since it uses more digits than its factorization.

668377609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 52.

The cubic root of 668377609 is about 874.3271492324.

The spelling of 668377609 in words is "six hundred sixty-eight million, three hundred seventy-seven thousand, six hundred nine".