668071823 has 4 divisors (see below), whose sum is σ = 697118448. Its totient is φ = 639025200.

The previous prime is 668071801. The next prime is 668071843. The reversal of 668071823 is 328170866.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 328170866 = 2 ⋅164085433.

It is a cyclic number.

It is not a de Polignac number, because 668071823 - 2¹² = 668067727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668071843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14523278 + ... + 14523323.

It is an arithmetic number, because the mean of its divisors is an integer number (174279612).

Almost surely, 2^668071823 is an apocalyptic number.

668071823 is a deficient number, since it is larger than the sum of its proper divisors (29046625).

668071823 is a wasteful number, since it uses less digits than its factorization.

668071823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29046624.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 668071823 is about 25847.0853869445. The cubic root of 668071823 is about 874.1937925885.

The spelling of 668071823 in words is "six hundred sixty-eight million, seventy-one thousand, eight hundred twenty-three".