66814678 has 64 divisors (see below), whose sum is σ = 128471040. Its totient is φ = 25404192.

The previous prime is 66814673. The next prime is 66814681. The reversal of 66814678 is 87641866.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66814673) 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, 409825 + ... + 409987.

It is an arithmetic number, because the mean of its divisors is an integer number (2007360).

Almost surely, 2^66814678 is an apocalyptic number.

66814678 is a deficient number, since it is larger than the sum of its proper divisors (61656362).

66814678 is a wasteful number, since it uses less digits than its factorization.

66814678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281.

The product of its digits is 387072, while the sum is 46.

The square root of 66814678 is about 8174.0245901269. The cubic root of 66814678 is about 405.7799895125.

The spelling of 66814678 in words is "sixty-six million, eight hundred fourteen thousand, six hundred seventy-eight".