64991394715 has 8 divisors (see below), whose sum is σ = 83988879408. Its totient is φ = 47993645280.

The previous prime is 64991394707. The next prime is 64991394731. The reversal of 64991394715 is 51749319946.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 64991394715 - 2³ = 64991394707 is a prime.

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 64991394715.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 499933741 + ... + 499933870.

It is an arithmetic number, because the mean of its divisors is an integer number (10498609926).

Almost surely, 2^64991394715 is an apocalyptic number.

64991394715 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

64991394715 is a deficient number, since it is larger than the sum of its proper divisors (18997484693).

64991394715 is a wasteful number, since it uses less digits than its factorization.

64991394715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999867629.

The product of its digits is 7348320, while the sum is 58.

The spelling of 64991394715 in words is "sixty-four billion, nine hundred ninety-one million, three hundred ninety-four thousand, seven hundred fifteen".