666312726 has 16 divisors (see below), whose sum is σ = 1332961200. Its totient is φ = 222048288.

The previous prime is 666312721. The next prime is 666312727. The reversal of 666312726 is 627213666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666312721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17140 + ... + 40328.

It is an arithmetic number, because the mean of its divisors is an integer number (83310075).

Almost surely, 2^666312726 is an apocalyptic number.

666312726 is an abundant number, since it is smaller than the sum of its proper divisors (666648474).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666312726 is a wasteful number, since it uses less digits than its factorization.

666312726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27983.

The product of its digits is 108864, while the sum is 39.

The square root of 666312726 is about 25813.0340332166. The cubic root of 666312726 is about 873.4258395430.

The spelling of 666312726 in words is "six hundred sixty-six million, three hundred twelve thousand, seven hundred twenty-six".