66356843813 has 8 divisors (see below), whose sum is σ = 72809542008. Its totient is φ = 60096763584.

The previous prime is 66356843809. The next prime is 66356843831. The reversal of 66356843813 is 31834865366.

It can be written as a sum of positive squares in 4 ways, for example, as 15245581729 + 51111262084 = 123473^2 + 226078^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66356843813 - 2² = 66356843809 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66356843843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48153770 + ... + 48155147.

It is an arithmetic number, because the mean of its divisors is an integer number (9101192751).

Almost surely, 2^66356843813 is an apocalyptic number.

It is an amenable number.

66356843813 is a deficient number, since it is larger than the sum of its proper divisors (6452698195).

66356843813 is a wasteful number, since it uses less digits than its factorization.

66356843813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96308983.

The product of its digits is 7464960, while the sum is 53.

The spelling of 66356843813 in words is "sixty-six billion, three hundred fifty-six million, eight hundred forty-three thousand, eight hundred thirteen".