66509670 has 16 divisors (see below), whose sum is σ = 159623280. Its totient is φ = 17735904.

The previous prime is 66509669. The next prime is 66509689. The reversal of 66509670 is 7690566.

It is a happy 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, 1108465 + ... + 1108524.

It is an arithmetic number, because the mean of its divisors is an integer number (9976455).

Almost surely, 2^66509670 is an apocalyptic number.

66509670 is an abundant number, since it is smaller than the sum of its proper divisors (93113610).

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

66509670 is a wasteful number, since it uses less digits than its factorization.

66509670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2216999.

The product of its (nonzero) digits is 68040, while the sum is 39.

The square root of 66509670 is about 8155.3460993388. The cubic root of 66509670 is about 405.1615877080.

The spelling of 66509670 in words is "sixty-six million, five hundred nine thousand, six hundred seventy".