77896781520 has 160 divisors (see below), whose sum is σ = 246263238144. Its totient is φ = 20364864000.

The previous prime is 77896781507. The next prime is 77896781549. The reversal of 77896781520 is 2518769877.

It is a super-2 number, since 2×77896781520² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2594595 + ... + 2624445.

Almost surely, 2^77896781520 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 77896781520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123131619072).

77896781520 is an abundant number, since it is smaller than the sum of its proper divisors (168366456624).

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

77896781520 is a wasteful number, since it uses less digits than its factorization.

77896781520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30081 (or 30075 counting only the distinct ones).

The product of its (nonzero) digits is 11854080, while the sum is 60.

The spelling of 77896781520 in words is "seventy-seven billion, eight hundred ninety-six million, seven hundred eighty-one thousand, five hundred twenty".