666366534 has 64 divisors (see below), whose sum is σ = 1560499200. Its totient is φ = 210361536.

The previous prime is 666366529. The next prime is 666366539. The reversal of 666366534 is 435663666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (666366529) and next prime (666366539).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 666366534.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666366539) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 125322 + ... + 130530.

It is an arithmetic number, because the mean of its divisors is an integer number (24382800).

Almost surely, 2^666366534 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666366534, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (780249600).

666366534 is an abundant number, since it is smaller than the sum of its proper divisors (894132666).

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

666366534 is a wasteful number, since it uses less digits than its factorization.

666366534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5346 (or 5340 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 45.

The square root of 666366534 is about 25814.0762763264. The cubic root of 666366534 is about 873.4493500412.

The spelling of 666366534 in words is "six hundred sixty-six million, three hundred sixty-six thousand, five hundred thirty-four".