81992251250 has 270 divisors, whose sum is σ = 195787502163. Its totient is φ = 25657632000.

The previous prime is 81992251223. The next prime is 81992251279. The reversal of 81992251250 is 5215229918.

It can be written as a sum of positive squares in 23 ways, for example, as 78059330881 + 3932920369 = 279391^2 + 62713^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=202475.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 921261206 + ... + 921261294.

Almost surely, 2^81992251250 is an apocalyptic number.

81992251250 is an abundant number, since it is smaller than the sum of its proper divisors (113795250913).

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

81992251250 is an equidigital number, since it uses as much as digits as its factorization.

81992251250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 44.

The spelling of 81992251250 in words is "eighty-one billion, nine hundred ninety-two million, two hundred fifty-one thousand, two hundred fifty".