81012658560 has 128 divisors (see below), whose sum is σ = 261865301760. Its totient is φ = 21299066880.

The previous prime is 81012658553. The next prime is 81012658561. The reversal of 81012658560 is 6585621018.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81012658561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 160822 + ... + 433461.

It is an arithmetic number, because the mean of its divisors is an integer number (2045822670).

Almost surely, 2^81012658560 is an apocalyptic number.

81012658560 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81012658560 is an abundant number, since it is smaller than the sum of its proper divisors (180852643200).

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

81012658560 is a wasteful number, since it uses less digits than its factorization.

81012658560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594376 (or 594364 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 42.

The spelling of 81012658560 in words is "eighty-one billion, twelve million, six hundred fifty-eight thousand, five hundred sixty".