64194867177821 has 4 divisors (see below), whose sum is σ = 64233376397952. Its totient is φ = 64156357957692.

The previous prime is 64194867177757. The next prime is 64194867177839. The reversal of 64194867177821 is 12877176849146.

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 64194867177821 - 2⁶ = 64194867177757 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 (64194867177121) 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 3 ways as a sum of consecutive naturals, for example, 19254607565 + ... + 19254610898.

It is an arithmetic number, because the mean of its divisors is an integer number (16058344099488).

Almost surely, 2^{64194867177821} is an apocalyptic number.

It is an amenable number.

64194867177821 is a deficient number, since it is larger than the sum of its proper divisors (38509220131).

64194867177821 is a wasteful number, since it uses less digits than its factorization.

64194867177821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38509220130.

The product of its digits is 227598336, while the sum is 71.

The spelling of 64194867177821 in words is "sixty-four trillion, one hundred ninety-four billion, eight hundred sixty-seven million, one hundred seventy-seven thousand, eight hundred twenty-one".