666490693 has 16 divisors (see below), whose sum is σ = 733380480. Its totient is φ = 600678400.

The previous prime is 666490681. The next prime is 666490709. The reversal of 666490693 is 396094666.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666490693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666490603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 793968 + ... + 794806.

It is an arithmetic number, because the mean of its divisors is an integer number (45836280).

Almost surely, 2^666490693 is an apocalyptic number.

It is an amenable number.

666490693 is a deficient number, since it is larger than the sum of its proper divisors (66889787).

666490693 is a wasteful number, since it uses less digits than its factorization.

666490693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388.

The product of its (nonzero) digits is 1259712, while the sum is 49.

The square root of 666490693 is about 25816.4810344090. The cubic root of 666490693 is about 873.5035943936.

The spelling of 666490693 in words is "six hundred sixty-six million, four hundred ninety thousand, six hundred ninety-three".