66650557 has 8 divisors (see below), whose sum is σ = 71220600. Its totient is φ = 62152704.

The previous prime is 66650513. The next prime is 66650593. The reversal of 66650557 is 75505666.

It can be written as a sum of positive squares in 4 ways, for example, as 41036836 + 25613721 = 6406^2 + 5061^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66650557 - 2¹¹ = 66648509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66650057) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16132 + ... + 19837.

It is an arithmetic number, because the mean of its divisors is an integer number (8902575).

Almost surely, 2^66650557 is an apocalyptic number.

It is an amenable number.

66650557 is a deficient number, since it is larger than the sum of its proper divisors (4570043).

66650557 is a wasteful number, since it uses less digits than its factorization.

66650557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36095.

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

The square root of 66650557 is about 8163.9792380922. The cubic root of 66650557 is about 405.4474696582.

The spelling of 66650557 in words is "sixty-six million, six hundred fifty thousand, five hundred fifty-seven".