65991647748 has 192 divisors, whose sum is σ = 175105082880. Its totient is φ = 19191693312.

The previous prime is 65991647731. The next prime is 65991647753. The reversal of 65991647748 is 84774619956.

It is a super-2 number, since 2×65991647748² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 161348568 + ... + 161348976.

It is an arithmetic number, because the mean of its divisors is an integer number (912005640).

Almost surely, 2^65991647748 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65991647748, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87552541440).

65991647748 is an abundant number, since it is smaller than the sum of its proper divisors (109113435132).

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

65991647748 is a wasteful number, since it uses less digits than its factorization.

65991647748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878 (or 876 counting only the distinct ones).

The product of its digits is 91445760, while the sum is 66.

The spelling of 65991647748 in words is "sixty-five billion, nine hundred ninety-one million, six hundred forty-seven thousand, seven hundred forty-eight".