64649128831 has 4 divisors (see below), whose sum is σ = 73884718672. Its totient is φ = 55413538992.

The previous prime is 64649128807. The next prime is 64649128849. The reversal of 64649128831 is 13882194646.

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

It is not a de Polignac number, because 64649128831 - 2⁷ = 64649128703 is a prime.

It is a super-2 number, since 2×64649128831² (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 (64649128631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4617794910 + ... + 4617794923.

It is an arithmetic number, because the mean of its divisors is an integer number (18471179668).

Almost surely, 2^64649128831 is an apocalyptic number.

64649128831 is a deficient number, since it is larger than the sum of its proper divisors (9235589841).

64649128831 is an equidigital number, since it uses as much as digits as its factorization.

64649128831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9235589840.

The product of its digits is 1990656, while the sum is 52.

The spelling of 64649128831 in words is "sixty-four billion, six hundred forty-nine million, one hundred twenty-eight thousand, eight hundred thirty-one".