66698746813 has 4 divisors (see below), whose sum is σ = 67957213788. Its totient is φ = 65440279840.

The previous prime is 66698746801. The next prime is 66698746949. The reversal of 66698746813 is 31864789666.

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

It can be written as a sum of positive squares in 2 ways, for example, as 27176511609 + 39522235204 = 164853^2 + 198802^2 .

It is a cyclic number.

It is not a de Polignac number, because 66698746813 - 2¹⁷ = 66698615741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66698746313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 629233408 + ... + 629233513.

It is an arithmetic number, because the mean of its divisors is an integer number (16989303447).

Almost surely, 2^66698746813 is an apocalyptic number.

It is an amenable number.

66698746813 is a deficient number, since it is larger than the sum of its proper divisors (1258466975).

66698746813 is a wasteful number, since it uses less digits than its factorization.

66698746813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1258466974.

The product of its digits is 62705664, while the sum is 64.

The spelling of 66698746813 in words is "sixty-six billion, six hundred ninety-eight million, seven hundred forty-six thousand, eight hundred thirteen".