81000015744 has 32 divisors (see below), whose sum is σ = 215156292840. Its totient is φ = 27000005120.

The previous prime is 81000015727. The next prime is 81000015769. The reversal of 81000015744 is 44751000018.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×81000015744² (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 (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105468387 + ... + 105469154.

Almost surely, 2^81000015744 is an apocalyptic number.

It is an amenable number.

81000015744 is an abundant number, since it is smaller than the sum of its proper divisors (134156277096).

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

81000015744 is a wasteful number, since it uses less digits than its factorization.

81000015744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210937558 (or 210937546 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

The spelling of 81000015744 in words is "eighty-one billion, fifteen thousand, seven hundred forty-four".