64665056646 has 128 divisors (see below), whose sum is σ = 158677401600. Its totient is φ = 19429074720.

The previous prime is 64665056629. The next prime is 64665056647.

64665056646 is nontrivially palindromic in base 10.

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

It is a junction number, because it is equal to n+sod(n) for n = 64665056592 and 64665056601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64665056647) 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 63 ways as a sum of consecutive naturals, for example, 4500045 + ... + 4514391.

It is an arithmetic number, because the mean of its divisors is an integer number (1239667200).

Almost surely, 2^64665056646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64665056646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79338700800).

64665056646 is an abundant number, since it is smaller than the sum of its proper divisors (94012344954).

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

64665056646 is a wasteful number, since it uses less digits than its factorization.

64665056646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14591 (or 14585 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 54.

The spelling of 64665056646 in words is "sixty-four billion, six hundred sixty-five million, fifty-six thousand, six hundred forty-six".