81393716250 has 720 divisors, whose sum is σ = 289341980928. Its totient is φ = 16329600000.

The previous prime is 81393716227. The next prime is 81393716273. The reversal of 81393716250 is 5261739318.

81393716250 is a `hidden beast` number, since 8 + 1 + 393 + 7 + 1 + 6 + 250 = 666.

It is an interprime number because it is at equal distance from previous prime (81393716227) and next prime (81393716273).

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 = 81393716196 and 81393716205.

It is an unprimeable number.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 187976034 + ... + 187976466.

Almost surely, 2^81393716250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81393716250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144670990464).

81393716250 is an abundant number, since it is smaller than the sum of its proper divisors (207948264678).

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

81393716250 is a wasteful number, since it uses less digits than its factorization.

81393716250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 492 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 81393716250 in words is "eighty-one billion, three hundred ninety-three million, seven hundred sixteen thousand, two hundred fifty".