81156135570960 has 320 divisors, whose sum is σ = 266552396697600. Its totient is φ = 20385168697344.

The previous prime is 81156135570959. The next prime is 81156135571057. The reversal of 81156135570960 is 6907553165118.

It is a self number, because there is not a number n which added to its sum of digits gives 81156135570960.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 101373526 + ... + 102170954.

It is an arithmetic number, because the mean of its divisors is an integer number (832976239680).

Almost surely, 2^{81156135570960} is an apocalyptic number.

81156135570960 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81156135570960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133276198348800).

81156135570960 is an abundant number, since it is smaller than the sum of its proper divisors (185396261126640).

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

81156135570960 is a wasteful number, since it uses less digits than its factorization.

81156135570960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797750 (or 797744 counting only the distinct ones).

The product of its (nonzero) digits is 6804000, while the sum is 57.

The spelling of 81156135570960 in words is "eighty-one trillion, one hundred fifty-six billion, one hundred thirty-five million, five hundred seventy thousand, nine hundred sixty".