668726111 has 4 divisors (see below), whose sum is σ = 668803800. Its totient is φ = 668648424.

The previous prime is 668726101. The next prime is 668726143. The reversal of 668726111 is 111627866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 668726111 - 2¹⁸ = 668463967 is a prime.

It is a super-2 number, since 2×668726111² = 894389223066368642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668726101) 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, 24056 + ... + 43773.

It is an arithmetic number, because the mean of its divisors is an integer number (167200950).

Almost surely, 2^668726111 is an apocalyptic number.

668726111 is a deficient number, since it is larger than the sum of its proper divisors (77689).

668726111 is an equidigital number, since it uses as much as digits as its factorization.

668726111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77688.

The product of its digits is 24192, while the sum is 38.

The square root of 668726111 is about 25859.7391904868. The cubic root of 668726111 is about 874.4790852100.

The spelling of 668726111 in words is "six hundred sixty-eight million, seven hundred twenty-six thousand, one hundred eleven".