81250000000 has 192 divisors, whose sum is σ = 217895506920. Its totient is φ = 30000000000.

The previous prime is 81249999977. The next prime is 81250000199. The reversal of 81250000000 is 5218.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 2908229184 + 78341770816 = 53928^2 + 279896^2 .

It is a sliding number, since 81250000000 = 1250000000 + 80000000000 and 1/1250000000 + 1/80000000000 = 0.00000000081250000000.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6249999994 + ... + 6250000006.

Almost surely, 2^81250000000 is an apocalyptic number.

81250000000 is a gapful number since it is divisible by the number (80) 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 81250000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108947753460).

81250000000 is an abundant number, since it is smaller than the sum of its proper divisors (136645506920).

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

81250000000 is an frugal number, since it uses more digits than its factorization.

81250000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

Adding to 81250000000 its reverse (5218), we get a palindrome (81250005218).

It can be divided in two parts, 8 and 1250000000, that multiplied together give a 10-th power (10000000000 = 10¹⁰).

The spelling of 81250000000 in words is "eighty-one billion, two hundred fifty million", and thus it is an aban number.