81243557684880 has 160 divisors (see below), whose sum is σ = 254394072987264. Its totient is φ = 21446831443968.

The previous prime is 81243557684873. The next prime is 81243557684953. The reversal of 81243557684880 is 8848675534218.

81243557684880 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×81243557684880² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34106532 + ... + 36410748.

Almost surely, 2^{81243557684880} is an apocalyptic number.

81243557684880 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 81243557684880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127197036493632).

81243557684880 is an abundant number, since it is smaller than the sum of its proper divisors (173150515302384).

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

81243557684880 is a wasteful number, since it uses less digits than its factorization.

81243557684880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2305713 (or 2305707 counting only the distinct ones).

The product of its (nonzero) digits is 412876800, while the sum is 69.

The spelling of 81243557684880 in words is "eighty-one trillion, two hundred forty-three billion, five hundred fifty-seven million, six hundred eighty-four thousand, eight hundred eighty".