81280869120 has 1440 divisors, whose sum is σ = 347599042560. Its totient is φ = 18065203200.

The previous prime is 81280869107. The next prime is 81280869193. The reversal of 81280869120 is 2196808218.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1440).

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

It is an unprimeable number.

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 159 ways as a sum of consecutive naturals, for example, 2621963505 + ... + 2621963535.

It is an arithmetic number, because the mean of its divisors is an integer number (241388224).

Almost surely, 2^81280869120 is an apocalyptic number.

81280869120 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 81280869120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (173799521280).

81280869120 is an abundant number, since it is smaller than the sum of its proper divisors (266318173440).

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

81280869120 is a wasteful number, since it uses less digits than its factorization.

81280869120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The spelling of 81280869120 in words is "eighty-one billion, two hundred eighty million, eight hundred sixty-nine thousand, one hundred twenty".