66776321613 has 16 divisors (see below), whose sum is σ = 95417168256. Its totient is φ = 41431135680.

The previous prime is 66776321609. The next prime is 66776321627. The reversal of 66776321613 is 31612367766.

It is not a de Polignac number, because 66776321613 - 2² = 66776321609 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66776321713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13075458 + ... + 13080563.

It is an arithmetic number, because the mean of its divisors is an integer number (5963573016).

Almost surely, 2^66776321613 is an apocalyptic number.

It is an amenable number.

66776321613 is a deficient number, since it is larger than the sum of its proper divisors (28640846643).

66776321613 is a wasteful number, since it uses less digits than its factorization.

66776321613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26156084.

The product of its digits is 1143072, while the sum is 48.

The spelling of 66776321613 in words is "sixty-six billion, seven hundred seventy-six million, three hundred twenty-one thousand, six hundred thirteen".