65644444656 has 480 divisors, whose sum is σ = 229885286400. Its totient is φ = 17862405120.

The previous prime is 65644444651. The next prime is 65644444673.

65644444656 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×65644444656² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65644444651) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 37318305 + ... + 37320063.

It is an arithmetic number, because the mean of its divisors is an integer number (478927680).

Almost surely, 2^65644444656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65644444656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114942643200).

65644444656 is an abundant number, since it is smaller than the sum of its proper divisors (164240841744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65644444656 is a wasteful number, since it uses less digits than its factorization.

65644444656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1874 (or 1855 counting only the distinct ones).

The product of its digits is 33177600, while the sum is 54.

The spelling of 65644444656 in words is "sixty-five billion, six hundred forty-four million, four hundred forty-four thousand, six hundred fifty-six".