81428538 has 16 divisors (see below), whose sum is σ = 172437120. Its totient is φ = 25546176.

The previous prime is 81428531. The next prime is 81428569. The reversal of 81428538 is 83582418.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81428496 and 81428505.

It is not an unprimeable number, because it can be changed into a prime (81428531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 399058 + ... + 399261.

It is an arithmetic number, because the mean of its divisors is an integer number (10777320).

Almost surely, 2^81428538 is an apocalyptic number.

81428538 is an abundant number, since it is smaller than the sum of its proper divisors (91008582).

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

81428538 is a wasteful number, since it uses less digits than its factorization.

81428538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798341.

The product of its digits is 61440, while the sum is 39.

The square root of 81428538 is about 9023.7762605242. The cubic root of 81428538 is about 433.4365648861.

The spelling of 81428538 in words is "eighty-one million, four hundred twenty-eight thousand, five hundred thirty-eight".