64537637985891 has 12 divisors (see below), whose sum is σ = 106538323024432. Its totient is φ = 36878650277616.

The previous prime is 64537637985809. The next prime is 64537637985937. The reversal of 64537637985891 is 19858973673546.

64537637985891 is a `hidden beast` number, since 6 + 4 + 537 + 6 + 3 + 79 + 8 + 5 + 8 + 9 + 1 = 666.

It is not a de Polignac number, because 64537637985891 - 2¹⁷ = 64537637854819 is a prime.

It is a super-4 number, since 4×64537637985891⁴ (a number of 56 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64537637985891.

It is not an unprimeable number, because it can be changed into a prime (64537637984891) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 512203476016 + ... + 512203476141.

Almost surely, 2^{64537637985891} is an apocalyptic number.

64537637985891 is a deficient number, since it is larger than the sum of its proper divisors (42000685038541).

64537637985891 is a wasteful number, since it uses less digits than its factorization.

64537637985891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1024406952170 (or 1024406952167 counting only the distinct ones).

The product of its digits is 8230118400, while the sum is 81.

The spelling of 64537637985891 in words is "sixty-four trillion, five hundred thirty-seven billion, six hundred thirty-seven million, nine hundred eighty-five thousand, eight hundred ninety-one".