81015450128 has 10 divisors (see below), whose sum is σ = 156967434654. Its totient is φ = 40507725056.

The previous prime is 81015450091. The next prime is 81015450143. The reversal of 81015450128 is 82105451018.

It can be written as a sum of positive squares in only one way, i.e., 77344059664 + 3671390464 = 278108^2 + 60592^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2531732801 + ... + 2531732832.

Almost surely, 2^81015450128 is an apocalyptic number.

It is an amenable number.

81015450128 is a deficient number, since it is larger than the sum of its proper divisors (75951984526).

81015450128 is a wasteful number, since it uses less digits than its factorization.

81015450128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5063465641 (or 5063465635 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 35.

The spelling of 81015450128 in words is "eighty-one billion, fifteen million, four hundred fifty thousand, one hundred twenty-eight".