669919967 has 2 divisors, whose sum is σ = 669919968. Its totient is φ = 669919966.

The previous prime is 669919963. The next prime is 669919979. The reversal of 669919967 is 769919966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 669919967 - 2² = 669919963 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669919963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334959983 + 334959984.

It is an arithmetic number, because the mean of its divisors is an integer number (334959984).

Almost surely, 2^669919967 is an apocalyptic number.

669919967 is a deficient number, since it is larger than the sum of its proper divisors (1).

669919967 is an equidigital number, since it uses as much as digits as its factorization.

669919967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9920232, while the sum is 62.

The square root of 669919967 is about 25882.8121926502. The cubic root of 669919967 is about 874.9991693053. Note that the first 3 decimals are identical.

Subtracting 669919967 from its reverse (769919966), we obtain a palindrome (99999999).

The spelling of 669919967 in words is "six hundred sixty-nine million, nine hundred nineteen thousand, nine hundred sixty-seven".