66520131 has 4 divisors (see below), whose sum is σ = 88693512. Its totient is φ = 44346752.

The previous prime is 66520063. The next prime is 66520151. The reversal of 66520131 is 13102566.

66520131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66520131 - 2¹⁰ = 66519107 is a prime.

It is a super-2 number, since 2×66520131² = 8849855656514322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66520151) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 11086686 + ... + 11086691.

It is an arithmetic number, because the mean of its divisors is an integer number (22173378).

Almost surely, 2^66520131 is an apocalyptic number.

66520131 is a deficient number, since it is larger than the sum of its proper divisors (22173381).

66520131 is a wasteful number, since it uses less digits than its factorization.

66520131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22173380.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 66520131 is about 8155.9874325553. The cubic root of 66520131 is about 405.1828285951.

Adding to 66520131 its reverse (13102566), we get a palindrome (79622697).

The spelling of 66520131 in words is "sixty-six million, five hundred twenty thousand, one hundred thirty-one".