66621650 has 12 divisors (see below), whose sum is σ = 123916362. Its totient is φ = 26648640.

The previous prime is 66621649. The next prime is 66621661. The reversal of 66621650 is 5612666.

66621650 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 63856081 + 2765569 = 7991^2 + 1663^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 666167 + ... + 666266.

Almost surely, 2^66621650 is an apocalyptic number.

66621650 is a deficient number, since it is larger than the sum of its proper divisors (57294712).

66621650 is a wasteful number, since it uses less digits than its factorization.

66621650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1332445 (or 1332440 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 66621650 is about 8162.2086471739. The cubic root of 66621650 is about 405.3888456679.

The spelling of 66621650 in words is "sixty-six million, six hundred twenty-one thousand, six hundred fifty".