81361128 has 32 divisors (see below), whose sum is σ = 206193600. Its totient is φ = 26748288.

The previous prime is 81361127. The next prime is 81361139. The reversal of 81361128 is 82116318.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 81361095 and 81361104.

It is not an unprimeable number, because it can be changed into a prime (81361123) 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, 21468 + ... + 24971.

It is an arithmetic number, because the mean of its divisors is an integer number (6443550).

Almost surely, 2^81361128 is an apocalyptic number.

It is an amenable number.

81361128 is an abundant number, since it is smaller than the sum of its proper divisors (124832472).

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

81361128 is a wasteful number, since it uses less digits than its factorization.

81361128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46521 (or 46517 counting only the distinct ones).

The product of its digits is 2304, while the sum is 30.

The square root of 81361128 is about 9020.0403546769. The cubic root of 81361128 is about 433.3169261375.

The spelling of 81361128 in words is "eighty-one million, three hundred sixty-one thousand, one hundred twenty-eight".