81444274560 has 768 divisors, whose sum is σ = 329126353920. Its totient is φ = 18338611200.

The previous prime is 81444274559. The next prime is 81444274567. The reversal of 81444274560 is 6547244418.

81444274560 is a `hidden beast` number, since 8 + 1 + 44 + 42 + 7 + 4 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81444274567) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 89400505 + ... + 89401415.

It is an arithmetic number, because the mean of its divisors is an integer number (428549940).

Almost surely, 2^81444274560 is an apocalyptic number.

81444274560 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 81444274560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164563176960).

81444274560 is an abundant number, since it is smaller than the sum of its proper divisors (247682079360).

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

81444274560 is a wasteful number, since it uses less digits than its factorization.

81444274560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1047 (or 1032 counting only the distinct ones).

The product of its (nonzero) digits is 860160, while the sum is 45.

The spelling of 81444274560 in words is "eighty-one billion, four hundred forty-four million, two hundred seventy-four thousand, five hundred sixty".