66820341637 has 4 divisors (see below), whose sum is σ = 76366104736. Its totient is φ = 57274578540.

The previous prime is 66820341629. The next prime is 66820341649. The reversal of 66820341637 is 73614302866.

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 66820341637 - 2³ = 66820341629 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 (66820341667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4772881539 + ... + 4772881552.

It is an arithmetic number, because the mean of its divisors is an integer number (19091526184).

Almost surely, 2^66820341637 is an apocalyptic number.

It is an amenable number.

66820341637 is a deficient number, since it is larger than the sum of its proper divisors (9545763099).

66820341637 is an equidigital number, since it uses as much as digits as its factorization.

66820341637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9545763098.

The product of its (nonzero) digits is 870912, while the sum is 46.

The spelling of 66820341637 in words is "sixty-six billion, eight hundred twenty million, three hundred forty-one thousand, six hundred thirty-seven".