64491001633 has 4 divisors (see below), whose sum is σ = 64491641748. Its totient is φ = 64490361520.

The previous prime is 64491001609. The next prime is 64491001651. The reversal of 64491001633 is 33610019446.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 33610019446 = 2 ⋅16805009723.

It can be written as a sum of positive squares in 2 ways, for example, as 17468380224 + 47022621409 = 132168^2 + 216847^2 .

It is a cyclic number.

It is not a de Polignac number, because 64491001633 - 2⁹ = 64491001121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64491001592 and 64491001601.

It is not an unprimeable number, because it can be changed into a prime (64491001033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132166 + ... + 382687.

It is an arithmetic number, because the mean of its divisors is an integer number (16122910437).

Almost surely, 2^64491001633 is an apocalyptic number.

It is an amenable number.

64491001633 is a deficient number, since it is larger than the sum of its proper divisors (640115).

64491001633 is a wasteful number, since it uses less digits than its factorization.

64491001633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640114.

The product of its (nonzero) digits is 46656, while the sum is 37.

The spelling of 64491001633 in words is "sixty-four billion, four hundred ninety-one million, one thousand, six hundred thirty-three".