666377839 has 2 divisors, whose sum is σ = 666377840. Its totient is φ = 666377838.

The previous prime is 666377821. The next prime is 666377857. The reversal of 666377839 is 938773666.

It is a balanced prime because it is at equal distance from previous prime (666377821) and next prime (666377857).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666377839 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666377839.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666377819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333188919 + 333188920.

It is an arithmetic number, because the mean of its divisors is an integer number (333188920).

Almost surely, 2^666377839 is an apocalyptic number.

666377839 is a deficient number, since it is larger than the sum of its proper divisors (1).

666377839 is an equidigital number, since it uses as much as digits as its factorization.

666377839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6858432, while the sum is 55.

The square root of 666377839 is about 25814.2952450769. The cubic root of 666377839 is about 873.4542894094.

The spelling of 666377839 in words is "six hundred sixty-six million, three hundred seventy-seven thousand, eight hundred thirty-nine".