81308776050 has 240 divisors, whose sum is σ = 233378667720. Its totient is φ = 20977781760.

The previous prime is 81308776049. The next prime is 81308776057. The reversal of 81308776050 is 5067780318.

81308776050 is a `hidden beast` number, since 8 + 1 + 30 + 8 + 7 + 7 + 605 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 22473907569 + 58834868481 = 149913^2 + 242559^2 .

It is a super-2 number, since 2×81308776050² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 81308775987 and 81308776005.

It is not an unprimeable number, because it can be changed into a prime (81308776057) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 15666856 + ... + 15672044.

Almost surely, 2^81308776050 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81308776050, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116689333860).

81308776050 is an abundant number, since it is smaller than the sum of its proper divisors (152069891670).

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

81308776050 is a wasteful number, since it uses less digits than its factorization.

81308776050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5339 (or 5325 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The spelling of 81308776050 in words is "eighty-one billion, three hundred eight million, seven hundred seventy-six thousand, fifty".