66878740 has 24 divisors (see below), whose sum is σ = 141073632. Its totient is φ = 26631840.

The previous prime is 66878659. The next prime is 66878743. The reversal of 66878740 is 4787866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66878743) 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, 2826 + ... + 11905.

It is an arithmetic number, because the mean of its divisors is an integer number (5878068).

Almost surely, 2^66878740 is an apocalyptic number.

It is an amenable number.

66878740 is an abundant number, since it is smaller than the sum of its proper divisors (74194892).

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

66878740 is a wasteful number, since it uses less digits than its factorization.

66878740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14967 (or 14965 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 46.

The square root of 66878740 is about 8177.9422839734. The cubic root of 66878740 is about 405.9096355466.

The spelling of 66878740 in words is "sixty-six million, eight hundred seventy-eight thousand, seven hundred forty".