666783427 has 2 divisors, whose sum is σ = 666783428. Its totient is φ = 666783426.

The previous prime is 666783419. The next prime is 666783443. The reversal of 666783427 is 724387666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666783427 - 2³ = 666783419 is a prime.

It is not a weakly prime, because it can be changed into another prime (666783487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333391713 + 333391714.

It is an arithmetic number, because the mean of its divisors is an integer number (333391714).

Almost surely, 2^666783427 is an apocalyptic number.

666783427 is a deficient number, since it is larger than the sum of its proper divisors (1).

666783427 is an equidigital number, since it uses as much as digits as its factorization.

666783427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2032128, while the sum is 49.

The square root of 666783427 is about 25822.1499298567. The cubic root of 666783427 is about 873.6314615323.

The spelling of 666783427 in words is "six hundred sixty-six million, seven hundred eighty-three thousand, four hundred twenty-seven".