668999743 has 2 divisors, whose sum is σ = 668999744. Its totient is φ = 668999742.

The previous prime is 668999741. The next prime is 668999767. The reversal of 668999743 is 347999866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668999743 - 2¹ = 668999741 is a prime.

It is a super-2 number, since 2×668999743² = 895121312268132098, which contains 22 as substring.

Together with 668999741, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668999741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334499871 + 334499872.

It is an arithmetic number, because the mean of its divisors is an integer number (334499872).

Almost surely, 2^668999743 is an apocalyptic number.

668999743 is a deficient number, since it is larger than the sum of its proper divisors (1).

668999743 is an equidigital number, since it uses as much as digits as its factorization.

668999743 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17635968, while the sum is 61.

The square root of 668999743 is about 25865.0293446576. The cubic root of 668999743 is about 874.5983432178.

The spelling of 668999743 in words is "six hundred sixty-eight million, nine hundred ninety-nine thousand, seven hundred forty-three".