64780070641821 has 18 divisors (see below), whose sum is σ = 97165169219742. Its totient is φ = 43186713756840.

The previous prime is 64780070641807. The next prime is 64780070641841. The reversal of 64780070641821 is 12814607008746.

64780070641821 is a `hidden beast` number, since 64 + 7 + 80 + 0 + 70 + 6 + 418 + 21 = 666.

64780070641821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 41917997796921 + 22862072844900 = 6474411^2 + 4781430^2 .

It is a de Polignac number, because none of the positive numbers 2^k-64780070641821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64780070641841) 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 17 ways as a sum of consecutive naturals, for example, 4936746270 + ... + 4936759391.

Almost surely, 2^{64780070641821} is an apocalyptic number.

It is an amenable number.

64780070641821 is a deficient number, since it is larger than the sum of its proper divisors (32385098577921).

64780070641821 is an frugal number, since it uses more digits than its factorization.

64780070641821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9873505685 (or 9873505664 counting only the distinct ones).

The product of its (nonzero) digits is 3612672, while the sum is 54.

The spelling of 64780070641821 in words is "sixty-four trillion, seven hundred eighty billion, seventy million, six hundred forty-one thousand, eight hundred twenty-one".