64636247809 has 16 divisors (see below), whose sum is σ = 76341404160. Its totient is φ = 53572861440.

The previous prime is 64636247807. The next prime is 64636247813. The reversal of 64636247809 is 90874263646.

It is not a de Polignac number, because 64636247809 - 2¹ = 64636247807 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 64636247809.

It is not an unprimeable number, because it can be changed into a prime (64636247807) 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 15 ways as a sum of consecutive naturals, for example, 964089 + ... + 1028950.

It is an arithmetic number, because the mean of its divisors is an integer number (4771337760).

Almost surely, 2^64636247809 is an apocalyptic number.

It is an amenable number.

64636247809 is a deficient number, since it is larger than the sum of its proper divisors (11705156351).

64636247809 is a wasteful number, since it uses less digits than its factorization.

64636247809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1993200.

The product of its (nonzero) digits is 10450944, while the sum is 55.

It can be divided in two parts, 64636 and 247809, that added together give a triangular number (312445 = T₇₉₀).

The spelling of 64636247809 in words is "sixty-four billion, six hundred thirty-six million, two hundred forty-seven thousand, eight hundred nine".