65787991992 has 240 divisors, whose sum is σ = 194066987400. Its totient is φ = 20815522560.

The previous prime is 65787991933. The next prime is 65787991993. The reversal of 65787991992 is 29919978756.

65787991992 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×65787991992² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 65787991992.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65787991993) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 33242059 + ... + 33244037.

Almost surely, 2^65787991992 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 65787991992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97033493700).

65787991992 is an abundant number, since it is smaller than the sum of its proper divisors (128278995408).

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

65787991992 is a wasteful number, since it uses less digits than its factorization.

65787991992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2116 (or 2074 counting only the distinct ones).

The product of its digits is 154314720, while the sum is 72.

The spelling of 65787991992 in words is "sixty-five billion, seven hundred eighty-seven million, nine hundred ninety-one thousand, nine hundred ninety-two".