81053768728 has 8 divisors (see below), whose sum is σ = 151975816380. Its totient is φ = 40526884360.

The previous prime is 81053768681. The next prime is 81053768743. The reversal of 81053768728 is 82786735018.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×81053768728² (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 as a sum of consecutive naturals, namely, 5065860538 + ... + 5065860553.

Almost surely, 2^81053768728 is an apocalyptic number.

It is an amenable number.

81053768728 is a deficient number, since it is larger than the sum of its proper divisors (70922047652).

81053768728 is a wasteful number, since it uses less digits than its factorization.

81053768728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10131721097 (or 10131721093 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 55.

The spelling of 81053768728 in words is "eighty-one billion, fifty-three million, seven hundred sixty-eight thousand, seven hundred twenty-eight".