668697041 has 4 divisors (see below), whose sum is σ = 686769972. Its totient is φ = 650624112.

The previous prime is 668697031. The next prime is 668697061. The reversal of 668697041 is 140796866.

It is a happy number.

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 356114641 + 312582400 = 18871^2 + 17680^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668697041 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668697011) 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, 9036410 + ... + 9036483.

It is an arithmetic number, because the mean of its divisors is an integer number (171692493).

Almost surely, 2^668697041 is an apocalyptic number.

It is an amenable number.

668697041 is a deficient number, since it is larger than the sum of its proper divisors (18072931).

668697041 is a wasteful number, since it uses less digits than its factorization.

668697041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18072930.

The product of its (nonzero) digits is 435456, while the sum is 47.

The square root of 668697041 is about 25859.1771137444. The cubic root of 668697041 is about 874.4664136170.

The spelling of 668697041 in words is "six hundred sixty-eight million, six hundred ninety-seven thousand, forty-one".