66590420 has 24 divisors (see below), whose sum is σ = 150597384. Its totient is φ = 24587136.

The previous prime is 66590401. The next prime is 66590441. The reversal of 66590420 is 2409566.

It can be written as a sum of positive squares in 4 ways, for example, as 15382084 + 51208336 = 3922^2 + 7156^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 127799 + ... + 128318.

It is an arithmetic number, because the mean of its divisors is an integer number (6274891).

Almost surely, 2^66590420 is an apocalyptic number.

It is an amenable number.

66590420 is an abundant number, since it is smaller than the sum of its proper divisors (84006964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66590420 is a wasteful number, since it uses less digits than its factorization.

66590420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256139 (or 256137 counting only the distinct ones).

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

The square root of 66590420 is about 8160.2953377926. The cubic root of 66590420 is about 405.3254915260.

Adding to 66590420 its reverse (2409566), we get a palindrome (68999986).

The spelling of 66590420 in words is "sixty-six million, five hundred ninety thousand, four hundred twenty".