81100609408 has 256 divisors, whose sum is σ = 202958784000. Its totient is φ = 31428550656.

The previous prime is 81100609399. The next prime is 81100609417. The reversal of 81100609408 is 80490600118.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81100609399) and next prime (81100609417).

It is a super-2 number, since 2×81100609408² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 144050535 + ... + 144051097.

It is an arithmetic number, because the mean of its divisors is an integer number (792807750).

Almost surely, 2^81100609408 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 81100609408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101479392000).

81100609408 is an abundant number, since it is smaller than the sum of its proper divisors (121858174592).

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

81100609408 is a wasteful number, since it uses less digits than its factorization.

81100609408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 829 (or 817 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 37.

The spelling of 81100609408 in words is "eighty-one billion, one hundred million, six hundred nine thousand, four hundred eight".