81547957590 has 128 divisors (see below), whose sum is σ = 219133804032. Its totient is φ = 19251025920.

The previous prime is 81547957553. The next prime is 81547957597. The reversal of 81547957590 is 9575974518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81547957597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4773504 + ... + 4790556.

It is an arithmetic number, because the mean of its divisors is an integer number (1711982844).

Almost surely, 2^81547957590 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81547957590, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109566902016).

81547957590 is an abundant number, since it is smaller than the sum of its proper divisors (137585846442).

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

81547957590 is a wasteful number, since it uses less digits than its factorization.

81547957590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17454.

The product of its (nonzero) digits is 15876000, while the sum is 60.

The spelling of 81547957590 in words is "eighty-one billion, five hundred forty-seven million, nine hundred fifty-seven thousand, five hundred ninety".