668098649 has 8 divisors (see below), whose sum is σ = 685992552. Its totient is φ = 650280960.

The previous prime is 668098633. The next prime is 668098667. The reversal of 668098649 is 946890866.

It can be written as a sum of positive squares in 4 ways, for example, as 38440000 + 629658649 = 6200^2 + 25093^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 668098649 - 2⁴ = 668098633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 668098594 and 668098603.

It is not an unprimeable number, because it can be changed into a prime (668098679) 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, 1064 + ... + 36569.

It is an arithmetic number, because the mean of its divisors is an integer number (85749069).

Almost surely, 2^668098649 is an apocalyptic number.

It is an amenable number.

668098649 is a deficient number, since it is larger than the sum of its proper divisors (17893903).

668098649 is a wasteful number, since it uses less digits than its factorization.

668098649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38107.

The product of its (nonzero) digits is 4478976, while the sum is 56.

The square root of 668098649 is about 25847.6043183890. The cubic root of 668098649 is about 874.2054933309.

The spelling of 668098649 in words is "six hundred sixty-eight million, ninety-eight thousand, six hundred forty-nine".