666864814 has 48 divisors (see below), whose sum is σ = 1344101040. Its totient is φ = 244527360.

The previous prime is 666864791. The next prime is 666864817. The reversal of 666864814 is 418468666.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666864817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 132 + ... + 36520.

It is an arithmetic number, because the mean of its divisors is an integer number (28002105).

Almost surely, 2^666864814 is an apocalyptic number.

666864814 is an abundant number, since it is smaller than the sum of its proper divisors (677236226).

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

666864814 is a wasteful number, since it uses less digits than its factorization.

666864814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36433 (or 36426 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 49.

The square root of 666864814 is about 25823.7257962518. The cubic root of 666864814 is about 873.6670049828.

The spelling of 666864814 in words is "six hundred sixty-six million, eight hundred sixty-four thousand, eight hundred fourteen".