65881536840 has 768 divisors, whose sum is σ = 274774291200. Its totient is φ = 13948526592.

The previous prime is 65881536839. The next prime is 65881536863. The reversal of 65881536840 is 4863518856.

65881536840 is a `hidden beast` number, since 6 + 588 + 1 + 53 + 6 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 60275334 + ... + 60276426.

It is an arithmetic number, because the mean of its divisors is an integer number (357779025).

Almost surely, 2^65881536840 is an apocalyptic number.

65881536840 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 65881536840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137387145600).

65881536840 is an abundant number, since it is smaller than the sum of its proper divisors (208892754360).

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

65881536840 is a wasteful number, since it uses less digits than its factorization.

65881536840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1211 (or 1194 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 54.

The spelling of 65881536840 in words is "sixty-five billion, eight hundred eighty-one million, five hundred thirty-six thousand, eight hundred forty".