66557590 has 16 divisors (see below), whose sum is σ = 130695120. Its totient is φ = 24202720.

The previous prime is 66557549. The next prime is 66557597. The reversal of 66557590 is 9575566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66557597) 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 7 ways as a sum of consecutive naturals, for example, 302425 + ... + 302644.

It is an arithmetic number, because the mean of its divisors is an integer number (8168445).

Almost surely, 2^66557590 is an apocalyptic number.

66557590 is a deficient number, since it is larger than the sum of its proper divisors (64137530).

66557590 is a wasteful number, since it uses less digits than its factorization.

66557590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605087.

The product of its (nonzero) digits is 283500, while the sum is 43.

The square root of 66557590 is about 8158.2835204472. The cubic root of 66557590 is about 405.2588702147.

The spelling of 66557590 in words is "sixty-six million, five hundred fifty-seven thousand, five hundred ninety".