81012761280 has 672 divisors, whose sum is σ = 322521315840. Its totient is φ = 18984499200.

The previous prime is 81012761267. The next prime is 81012761281. The reversal of 81012761280 is 8216721018.

81012761280 is a `hidden beast` number, since 8 + 10 + 1 + 27 + 612 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (81012761281) by changing a digit.

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 in 95 ways as a sum of consecutive naturals, for example, 91332997 + ... + 91333883.

Almost surely, 2^81012761280 is an apocalyptic number.

81012761280 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 81012761280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161260657920).

81012761280 is an abundant number, since it is smaller than the sum of its proper divisors (241508554560).

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

81012761280 is a wasteful number, since it uses less digits than its factorization.

81012761280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986 (or 939 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The spelling of 81012761280 in words is "eighty-one billion, twelve million, seven hundred sixty-one thousand, two hundred eighty".