64985311596221 has 4 divisors (see below), whose sum is σ = 68807976984252. Its totient is φ = 61162646208192.

The previous prime is 64985311596217. The next prime is 64985311596241. The reversal of 64985311596221 is 12269511358946.

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 56927945493721 + 8057366102500 = 7545061^2 + 2838550^2 .

It is a cyclic number.

It is not a de Polignac number, because 64985311596221 - 2² = 64985311596217 is a prime.

It is a super-3 number, since 3×64985311596221³ (a number of 42 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64985311596241) 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, 1911332693990 + ... + 1911332694023.

It is an arithmetic number, because the mean of its divisors is an integer number (17201994246063).

Almost surely, 2^{64985311596221} is an apocalyptic number.

It is an amenable number.

64985311596221 is a deficient number, since it is larger than the sum of its proper divisors (3822665388031).

64985311596221 is a wasteful number, since it uses less digits than its factorization.

64985311596221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3822665388030.

The product of its digits is 27993600, while the sum is 62.

The spelling of 64985311596221 in words is "sixty-four trillion, nine hundred eighty-five billion, three hundred eleven million, five hundred ninety-six thousand, two hundred twenty-one".