66640244 has 12 divisors (see below), whose sum is σ = 127222368. Its totient is φ = 30291000.

The previous prime is 66640237. The next prime is 66640253. The reversal of 66640244 is 44204666.

It is a self number, because there is not a number n which added to its sum of digits gives 66640244.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 757232 + ... + 757319.

It is an arithmetic number, because the mean of its divisors is an integer number (10601864).

Almost surely, 2^66640244 is an apocalyptic number.

It is an amenable number.

66640244 is a deficient number, since it is larger than the sum of its proper divisors (60582124).

66640244 is a wasteful number, since it uses less digits than its factorization.

66640244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1514566 (or 1514564 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 66640244 is about 8163.3475976464. The cubic root of 66640244 is about 405.4265566275.

The spelling of 66640244 in words is "sixty-six million, six hundred forty thousand, two hundred forty-four".