66945138 has 32 divisors (see below), whose sum is σ = 144969216. Its totient is φ = 20487168.

The previous prime is 66945107. The next prime is 66945163. The reversal of 66945138 is 83154966.

It is a self number, because there is not a number n which added to its sum of digits gives 66945138.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12831 + ... + 17277.

It is an arithmetic number, because the mean of its divisors is an integer number (4530288).

Almost surely, 2^66945138 is an apocalyptic number.

66945138 is an abundant number, since it is smaller than the sum of its proper divisors (78024078).

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

66945138 is a wasteful number, since it uses less digits than its factorization.

66945138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4658.

The product of its digits is 155520, while the sum is 42.

The square root of 66945138 is about 8182.0008555365. Note that the first 3 decimals coincide. The cubic root of 66945138 is about 406.0439217369.

The spelling of 66945138 in words is "sixty-six million, nine hundred forty-five thousand, one hundred thirty-eight".