81558235250 has 128 divisors (see below), whose sum is σ = 168337600704. Its totient is φ = 29460480000.

The previous prime is 81558235229. The next prime is 81558235259. The reversal of 81558235250 is 5253285518.

It can be written as a sum of positive squares in 32 ways, for example, as 55841943481 + 25716291769 = 236309^2 + 160363^2 .

It is not an unprimeable number, because it can be changed into a prime (81558235259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10625414 + ... + 10633086.

Almost surely, 2^81558235250 is an apocalyptic number.

81558235250 is an abundant number, since it is smaller than the sum of its proper divisors (86779365454).

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

81558235250 is a wasteful number, since it uses less digits than its factorization.

81558235250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7809 (or 7799 counting only the distinct ones).

The product of its (nonzero) digits is 480000, while the sum is 44.

The spelling of 81558235250 in words is "eighty-one billion, five hundred fifty-eight million, two hundred thirty-five thousand, two hundred fifty".