81000610944 has 128 divisors (see below), whose sum is σ = 235462006080. Its totient is φ = 24467804160.

The previous prime is 81000610913. The next prime is 81000610963. The reversal of 81000610944 is 44901600018.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×81000610944² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1308762 + ... + 1369254.

Almost surely, 2^81000610944 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 81000610944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117731003040).

81000610944 is an abundant number, since it is smaller than the sum of its proper divisors (154461395136).

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

81000610944 is a wasteful number, since it uses less digits than its factorization.

81000610944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60838 (or 60826 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The spelling of 81000610944 in words is "eighty-one billion, six hundred ten thousand, nine hundred forty-four".