66776513 has 4 divisors (see below), whose sum is σ = 66962880. Its totient is φ = 66590148.

The previous prime is 66776503. The next prime is 66776537. The reversal of 66776513 is 31567766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66776513 - 2⁴ = 66776497 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 (66776503) 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 3 ways as a sum of consecutive naturals, for example, 92645 + ... + 93362.

It is an arithmetic number, because the mean of its divisors is an integer number (16740720).

Almost surely, 2^66776513 is an apocalyptic number.

It is an amenable number.

66776513 is a deficient number, since it is larger than the sum of its proper divisors (186367).

66776513 is a wasteful number, since it uses less digits than its factorization.

66776513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186366.

The product of its digits is 158760, while the sum is 41.

The square root of 66776513 is about 8171.6897273453. The cubic root of 66776513 is about 405.7027133641.

The spelling of 66776513 in words is "sixty-six million, seven hundred seventy-six thousand, five hundred thirteen".