65721837888 has 896 divisors, whose sum is σ = 246492979200. Its totient is φ = 16740089856.

The previous prime is 65721837887. The next prime is 65721837931. The reversal of 65721837888 is 88873812756.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65721837887) by changing a digit.

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 127 ways as a sum of consecutive naturals, for example, 614222731 + ... + 614222837.

Almost surely, 2^65721837888 is an apocalyptic number.

65721837888 is a gapful number since it is divisible by the number (68) 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 65721837888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123246489600).

65721837888 is an abundant number, since it is smaller than the sum of its proper divisors (180771141312).

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

65721837888 is a wasteful number, since it uses less digits than its factorization.

65721837888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284 (or 268 counting only the distinct ones).

The product of its digits is 36126720, while the sum is 63.

The spelling of 65721837888 in words is "sixty-five billion, seven hundred twenty-one million, eight hundred thirty-seven thousand, eight hundred eighty-eight".