81084744540 has 36 divisors (see below), whose sum is σ = 245957058984. Its totient is φ = 21622598496.

The previous prime is 81084744529. The next prime is 81084744589. The reversal of 81084744540 is 4544748018.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 225235222 + ... + 225235581.

Almost surely, 2^81084744540 is an apocalyptic number.

It is an amenable number.

81084744540 is an abundant number, since it is smaller than the sum of its proper divisors (164872314444).

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

81084744540 is a wasteful number, since it uses less digits than its factorization.

81084744540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450470818 (or 450470813 counting only the distinct ones).

The product of its (nonzero) digits is 573440, while the sum is 45.

The spelling of 81084744540 in words is "eighty-one billion, eighty-four million, seven hundred forty-four thousand, five hundred forty".