65981347794 has 128 divisors (see below), whose sum is σ = 153280512000. Its totient is φ = 21015028800.

The previous prime is 65981347793. The next prime is 65981347813. The reversal of 65981347794 is 49774318956.

65981347794 is a `hidden beast` number, since 6 + 598 + 1 + 34 + 7 + 7 + 9 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (65981347793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 78642427 + ... + 78643265.

It is an arithmetic number, because the mean of its divisors is an integer number (1197504000).

Almost surely, 2^65981347794 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65981347794, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76640256000).

65981347794 is an abundant number, since it is smaller than the sum of its proper divisors (87299164206).

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

65981347794 is a wasteful number, since it uses less digits than its factorization.

65981347794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1421 (or 1415 counting only the distinct ones).

The product of its digits is 45722880, while the sum is 63.

The spelling of 65981347794 in words is "sixty-five billion, nine hundred eighty-one million, three hundred forty-seven thousand, seven hundred ninety-four".