65640604656 has 120 divisors (see below), whose sum is σ = 186627100240. Its totient is φ = 19865640960.

The previous prime is 65640604651. The next prime is 65640604657.

It is a happy number.

65640604656 is nontrivially palindromic in base 10.

65640604656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65640604651) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4808016 + ... + 4821648.

Almost surely, 2^65640604656 is an apocalyptic number.

65640604656 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65640604656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93313550120).

65640604656 is an abundant number, since it is smaller than the sum of its proper divisors (120986495584).

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

65640604656 is a wasteful number, since it uses less digits than its factorization.

65640604656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14495 (or 14478 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 65640604656 in words is "sixty-five billion, six hundred forty million, six hundred four thousand, six hundred fifty-six".