64728695791 has 4 divisors (see below), whose sum is σ = 65949991992. Its totient is φ = 63507399592.

The previous prime is 64728695767. The next prime is 64728695833. The reversal of 64728695791 is 19759682746.

64728695791 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64728695791 is a prime.

It is a super-2 number, since 2×64728695791² (a number of 22 digits) contains 22 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 (64728695701) 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, 610648021 + ... + 610648126.

It is an arithmetic number, because the mean of its divisors is an integer number (16487497998).

Almost surely, 2^64728695791 is an apocalyptic number.

64728695791 is a deficient number, since it is larger than the sum of its proper divisors (1221296201).

64728695791 is a wasteful number, since it uses less digits than its factorization.

64728695791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1221296200.

The product of its digits is 45722880, while the sum is 64.

The spelling of 64728695791 in words is "sixty-four billion, seven hundred twenty-eight million, six hundred ninety-five thousand, seven hundred ninety-one".