81003757572 has 72 divisors (see below), whose sum is σ = 220358443032. Its totient is φ = 24996326400.

The previous prime is 81003757517. The next prime is 81003757591. The reversal of 81003757572 is 27575730018.

81003757572 is a `hidden beast` number, since 8 + 1 + 0 + 0 + 3 + 7 + 575 + 72 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 14427372996 + 66576384576 = 120114^2 + 258024^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1047579 + ... + 1122242.

It is an arithmetic number, because the mean of its divisors is an integer number (3060533931).

Almost surely, 2^81003757572 is an apocalyptic number.

It is an amenable number.

81003757572 is an abundant number, since it is smaller than the sum of its proper divisors (139354685460).

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

81003757572 is a wasteful number, since it uses less digits than its factorization.

81003757572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2169909 (or 2169904 counting only the distinct ones).

The product of its (nonzero) digits is 411600, while the sum is 45.

The spelling of 81003757572 in words is "eighty-one billion, three million, seven hundred fifty-seven thousand, five hundred seventy-two".