66666590 has 16 divisors (see below), whose sum is σ = 120099888. Its totient is φ = 26644416.

The previous prime is 66666569. The next prime is 66666629. The reversal of 66666590 is 9566666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15629 + ... + 19431.

It is an arithmetic number, because the mean of its divisors is an integer number (7506243).

Almost surely, 2^66666590 is an apocalyptic number.

66666590 is a deficient number, since it is larger than the sum of its proper divisors (53433298).

66666590 is a wasteful number, since it uses less digits than its factorization.

66666590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5563.

The product of its (nonzero) digits is 349920, while the sum is 44.

The square root of 66666590 is about 8164.9611144206. The cubic root of 66666590 is about 405.4799776041.

The spelling of 66666590 in words is "sixty-six million, six hundred sixty-six thousand, five hundred ninety".