81055120 has 40 divisors (see below), whose sum is σ = 189612864. Its totient is φ = 32222592.

The previous prime is 81055109. The next prime is 81055127. The reversal of 81055120 is 2155018.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 81055091 and 81055100.

It is not an unprimeable number, because it can be changed into a prime (81055127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10327 + ... + 16393.

Almost surely, 2^81055120 is an apocalyptic number.

81055120 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 81055120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94806432).

81055120 is an abundant number, since it is smaller than the sum of its proper divisors (108557744).

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

81055120 is a wasteful number, since it uses less digits than its factorization.

81055120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6247 (or 6241 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 81055120 is about 9003.0617014436. The cubic root of 81055120 is about 432.7729930314.

It can be divided in two parts, 8105 and 5120, that added together give a square (13225 = 115²).

The spelling of 81055120 in words is "eighty-one million, fifty-five thousand, one hundred twenty".