65444120400 has 240 divisors, whose sum is σ = 213205461120. Its totient is φ = 17156505600.

The previous prime is 65444120323. The next prime is 65444120437. The reversal of 65444120400 is 402144456.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31447360 + ... + 31449440.

It is an arithmetic number, because the mean of its divisors is an integer number (888356088).

Almost surely, 2^65444120400 is an apocalyptic number.

65444120400 is a gapful number since it is divisible by the number (60) 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 65444120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106602730560).

65444120400 is an abundant number, since it is smaller than the sum of its proper divisors (147761340720).

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

65444120400 is a wasteful number, since it uses less digits than its factorization.

65444120400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2534 (or 2523 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 65444120400 its reverse (402144456), we get a palindrome (65846264856).

The spelling of 65444120400 in words is "sixty-five billion, four hundred forty-four million, one hundred twenty thousand, four hundred".