77891537500 has 144 divisors (see below), whose sum is σ = 195182507520. Its totient is φ = 26641800000.

The previous prime is 77891537467. The next prime is 77891537519. The reversal of 77891537500 is 573519877.

It is a super-2 number, since 2×77891537500² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 49961721 + ... + 49963279.

It is an arithmetic number, because the mean of its divisors is an integer number (1355434080).

Almost surely, 2^77891537500 is an apocalyptic number.

77891537500 is a gapful number since it is divisible by the number (70) 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 77891537500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97591253760).

77891537500 is an abundant number, since it is smaller than the sum of its proper divisors (117290970020).

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

77891537500 is a wasteful number, since it uses less digits than its factorization.

77891537500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2166 (or 2144 counting only the distinct ones).

The product of its (nonzero) digits is 1852200, while the sum is 52.

The spelling of 77891537500 in words is "seventy-seven billion, eight hundred ninety-one million, five hundred thirty-seven thousand, five hundred".