81344249280 has 1008 divisors, whose sum is σ = 353447823456. Its totient is φ = 17051811840.

The previous prime is 81344249243. The next prime is 81344249317. The reversal of 81344249280 is 8294244318.

81344249280 is a `hidden beast` number, since 8 + 1 + 344 + 24 + 9 + 280 = 666.

It is an interprime number because it is at equal distance from previous prime (81344249243) and next prime (81344249317).

It is a tau number, because it is divible by the number of its divisors (1008).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 98360227 + ... + 98361053.

It is an arithmetic number, because the mean of its divisors is an integer number (350642682).

Almost surely, 2^81344249280 is an apocalyptic number.

81344249280 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 81344249280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (176723911728).

81344249280 is an abundant number, since it is smaller than the sum of its proper divisors (272103574176).

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

81344249280 is a wasteful number, since it uses less digits than its factorization.

81344249280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 922 (or 902 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The spelling of 81344249280 in words is "eighty-one billion, three hundred forty-four million, two hundred forty-nine thousand, two hundred eighty".