65400344064 has 240 divisors, whose sum is σ = 206554748400. Its totient is φ = 19756154880.

The previous prime is 65400344029. The next prime is 65400344069. The reversal of 65400344064 is 46044300456.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65400344069) 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, 17688264 + ... + 17691960.

It is an arithmetic number, because the mean of its divisors is an integer number (860644785).

Almost surely, 2^65400344064 is an apocalyptic number.

65400344064 is a gapful number since it is divisible by the number (64) 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 65400344064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103277374200).

65400344064 is an abundant number, since it is smaller than the sum of its proper divisors (141154404336).

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

65400344064 is a wasteful number, since it uses less digits than its factorization.

65400344064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4081 (or 4062 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 36.

The spelling of 65400344064 in words is "sixty-five billion, four hundred million, three hundred forty-four thousand, sixty-four".