916668509989 has 2 divisors, whose sum is σ = 916668509990. Its totient is φ = 916668509988.

The previous prime is 916668509957. The next prime is 916668510029. The reversal of 916668509989 is 989905866619.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 524779989889 + 391888520100 = 724417^2 + 626010^2 .

It is an emirp because it is prime and its reverse (989905866619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 916668509989 - 2⁵ = 916668509957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (916668509909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 458334254994 + 458334254995.

It is an arithmetic number, because the mean of its divisors is an integer number (458334254995).

Almost surely, 2^916668509989 is an apocalyptic number.

It is an amenable number.

916668509989 is a deficient number, since it is larger than the sum of its proper divisors (1).

916668509989 is an equidigital number, since it uses as much as digits as its factorization.

916668509989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 453496320, while the sum is 76.

The spelling of 916668509989 in words is "nine hundred sixteen billion, six hundred sixty-eight million, five hundred nine thousand, nine hundred eighty-nine".