64997736457 has 4 divisors (see below), whose sum is σ = 65008231236. Its totient is φ = 64987241680.

The previous prime is 64997736413. The next prime is 64997736469. The reversal of 64997736457 is 75463779946.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75463779946 = 2 ⋅37731889973.

It can be written as a sum of positive squares in 2 ways, for example, as 43049610256 + 21948126201 = 207484^2 + 148149^2 .

It is a cyclic number.

It is not a de Polignac number, because 64997736457 - 2¹¹ = 64997734409 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64997736392 and 64997736401.

It is not an unprimeable number, because it can be changed into a prime (64997736157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5238094 + ... + 5250487.

It is an arithmetic number, because the mean of its divisors is an integer number (16252057809).

Almost surely, 2^64997736457 is an apocalyptic number.

It is an amenable number.

64997736457 is a deficient number, since it is larger than the sum of its proper divisors (10494779).

64997736457 is a wasteful number, since it uses less digits than its factorization.

64997736457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10494778.

The product of its digits is 240045120, while the sum is 67.

The spelling of 64997736457 in words is "sixty-four billion, nine hundred ninety-seven million, seven hundred thirty-six thousand, four hundred fifty-seven".