66644870 has 16 divisors (see below), whose sum is σ = 120087360. Its totient is φ = 26629824.

The previous prime is 66644867. The next prime is 66644873. The reversal of 66644870 is 7844666.

It is an interprime number because it is at equal distance from previous prime (66644867) and next prime (66644873).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66644873) 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, 8339 + ... + 14241.

It is an arithmetic number, because the mean of its divisors is an integer number (7505460).

Almost surely, 2^66644870 is an apocalyptic number.

66644870 is a deficient number, since it is larger than the sum of its proper divisors (53442490).

66644870 is a wasteful number, since it uses less digits than its factorization.

66644870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7039.

The product of its (nonzero) digits is 193536, while the sum is 41.

The square root of 66644870 is about 8163.6309323732. The cubic root of 66644870 is about 405.4359376448.

The spelling of 66644870 in words is "sixty-six million, six hundred forty-four thousand, eight hundred seventy".