65144365440 has 256 divisors, whose sum is σ = 258885987840. Its totient is φ = 13536460800.

The previous prime is 65144365339. The next prime is 65144365469. The reversal of 65144365440 is 4456344156.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 65144365392 and 65144365401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72481 + ... + 368160.

It is an arithmetic number, because the mean of its divisors is an integer number (1011273390).

Almost surely, 2^65144365440 is an apocalyptic number.

65144365440 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 65144365440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129442993920).

65144365440 is an abundant number, since it is smaller than the sum of its proper divisors (193741622400).

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

65144365440 is a wasteful number, since it uses less digits than its factorization.

65144365440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440681 (or 440669 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 42.

The spelling of 65144365440 in words is "sixty-five billion, one hundred forty-four million, three hundred sixty-five thousand, four hundred forty".