66251313 has 6 divisors (see below), whose sum is σ = 95696354. Its totient is φ = 44167536.

The previous prime is 66251299. The next prime is 66251357. The reversal of 66251313 is 31315266.

66251313 is a `hidden beast` number, since 6 + 625 + 1 + 31 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 36144144 + 30107169 = 6012^2 + 5487^2 .

It is not a de Polignac number, because 66251313 - 2⁵ = 66251281 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66251413) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3680620 + ... + 3680637.

Almost surely, 2^66251313 is an apocalyptic number.

It is an amenable number.

66251313 is a deficient number, since it is larger than the sum of its proper divisors (29445041).

66251313 is a wasteful number, since it uses less digits than its factorization.

66251313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7361263 (or 7361260 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 66251313 is about 8139.4909545991. The cubic root of 66251313 is about 404.6362898374.

Adding to 66251313 its reverse (31315266), we get a palindrome (97566579).

It can be divided in two parts, 66251 and 313, that added together give a square (66564 = 258²).

The spelling of 66251313 in words is "sixty-six million, two hundred fifty-one thousand, three hundred thirteen".