66557650 has 12 divisors (see below), whose sum is σ = 123797322. Its totient is φ = 26623040.

The previous prime is 66557633. The next prime is 66557657. The reversal of 66557650 is 5675566.

It can be written as a sum of positive squares in 3 ways, for example, as 59305401 + 7252249 = 7701^2 + 2693^2 .

It is not an unprimeable number, because it can be changed into a prime (66557657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 665527 + ... + 665626.

Almost surely, 2^66557650 is an apocalyptic number.

66557650 is a deficient number, since it is larger than the sum of its proper divisors (57239672).

66557650 is a wasteful number, since it uses less digits than its factorization.

66557650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1331165 (or 1331160 counting only the distinct ones).

The product of its (nonzero) digits is 189000, while the sum is 40.

The square root of 66557650 is about 8158.2871976905. The cubic root of 66557650 is about 405.2589919916.

The spelling of 66557650 in words is "sixty-six million, five hundred fifty-seven thousand, six hundred fifty".