81120428 has 24 divisors (see below), whose sum is σ = 150509184. Its totient is φ = 38188800.

The previous prime is 81120407. The next prime is 81120433. The reversal of 81120428 is 82402118.

It is a junction number, because it is equal to n+sod(n) for n = 81120397 and 81120406.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4253 + ... + 13428.

It is an arithmetic number, because the mean of its divisors is an integer number (6271216).

Almost surely, 2^81120428 is an apocalyptic number.

It is an amenable number.

81120428 is a deficient number, since it is larger than the sum of its proper divisors (69388756).

81120428 is a wasteful number, since it uses less digits than its factorization.

81120428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17753 (or 17751 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 81120428 is about 9006.6879595110. The cubic root of 81120428 is about 432.8891935921.

The spelling of 81120428 in words is "eighty-one million, one hundred twenty thousand, four hundred twenty-eight".