81503944236 has 108 divisors (see below), whose sum is σ = 243875837296. Its totient is φ = 22798290240.

The previous prime is 81503944201. The next prime is 81503944261. The reversal of 81503944236 is 63244930518.

81503944236 is a `hidden beast` number, since 81 + 503 + 9 + 44 + 23 + 6 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 81503944191 and 81503944200.

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 35 ways as a sum of consecutive naturals, for example, 663016 + ... + 776271.

Almost surely, 2^81503944236 is an apocalyptic number.

It is an amenable number.

81503944236 is an abundant number, since it is smaller than the sum of its proper divisors (162371893060).

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

81503944236 is a wasteful number, since it uses less digits than its factorization.

81503944236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439332 (or 1439316 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 81503944236 in words is "eighty-one billion, five hundred three million, nine hundred forty-four thousand, two hundred thirty-six".