81611249832 has 96 divisors (see below), whose sum is σ = 252819852480. Its totient is φ = 23297783040.

The previous prime is 81611249717. The next prime is 81611249843. The reversal of 81611249832 is 23894211618.

81611249832 is a `hidden beast` number, since 8 + 1 + 611 + 24 + 9 + 8 + 3 + 2 = 666.

It is a super-2 number, since 2×81611249832² (a number of 23 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 533407 + ... + 669137.

It is an arithmetic number, because the mean of its divisors is an integer number (2633540130).

Almost surely, 2^81611249832 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81611249832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126409926240).

81611249832 is an abundant number, since it is smaller than the sum of its proper divisors (171208602648).

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

81611249832 is a wasteful number, since it uses less digits than its factorization.

81611249832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136943 (or 136936 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The spelling of 81611249832 in words is "eighty-one billion, six hundred eleven million, two hundred forty-nine thousand, eight hundred thirty-two".