81536250000 has 320 divisors, whose sum is σ = 278999285760. Its totient is φ = 20448000000.

The previous prime is 81536249987. The next prime is 81536250011. The reversal of 81536250000 is 5263518.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 81536250000.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 63749361 + ... + 63750639.

It is an arithmetic number, because the mean of its divisors is an integer number (871872768).

Almost surely, 2^81536250000 is an apocalyptic number.

81536250000 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 81536250000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139499642880).

81536250000 is an abundant number, since it is smaller than the sum of its proper divisors (197463035760).

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

81536250000 is an equidigital number, since it uses as much as digits as its factorization.

81536250000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1342 (or 1306 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 81536250000 in words is "eighty-one billion, five hundred thirty-six million, two hundred fifty thousand".