81503661424 has 10 divisors (see below), whose sum is σ = 157913344040. Its totient is φ = 40751830704.

The previous prime is 81503661413. The next prime is 81503661431. The reversal of 81503661424 is 42416630518.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2546989404 + ... + 2546989435.

It is an arithmetic number, because the mean of its divisors is an integer number (15791334404).

Almost surely, 2^81503661424 is an apocalyptic number.

It is an amenable number.

81503661424 is a deficient number, since it is larger than the sum of its proper divisors (76409682616).

81503661424 is a wasteful number, since it uses less digits than its factorization.

81503661424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5093978847 (or 5093978841 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 81503661424 in words is "eighty-one billion, five hundred three million, six hundred sixty-one thousand, four hundred twenty-four".