666683623 has 2 divisors, whose sum is σ = 666683624. Its totient is φ = 666683622.

The previous prime is 666683621. The next prime is 666683783. The reversal of 666683623 is 326386666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666683623 - 2¹ = 666683621 is a prime.

It is a super-2 number, since 2×666683623² = 888934106352812258, which contains 22 as substring.

Together with 666683621, 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 (666683621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333341811 + 333341812.

It is an arithmetic number, because the mean of its divisors is an integer number (333341812).

Almost surely, 2^666683623 is an apocalyptic number.

666683623 is a deficient number, since it is larger than the sum of its proper divisors (1).

666683623 is an equidigital number, since it uses as much as digits as its factorization.

666683623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 46.

The square root of 666683623 is about 25820.2173306113. The cubic root of 666683623 is about 873.5878710343.

The spelling of 666683623 in words is "six hundred sixty-six million, six hundred eighty-three thousand, six hundred twenty-three".