81428582 has 8 divisors (see below), whose sum is σ = 122584656. Its totient is φ = 40567032.

The previous prime is 81428569. The next prime is 81428587. The reversal of 81428582 is 28582418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81428582² = 13261227933061448, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81428587) 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 3 ways as a sum of consecutive naturals, for example, 72938 + ... + 74045.

It is an arithmetic number, because the mean of its divisors is an integer number (15323082).

Almost surely, 2^81428582 is an apocalyptic number.

81428582 is a deficient number, since it is larger than the sum of its proper divisors (41156074).

81428582 is a wasteful number, since it uses less digits than its factorization.

81428582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147262.

The product of its digits is 40960, while the sum is 38.

The square root of 81428582 is about 9023.7786985276. The cubic root of 81428582 is about 433.4366429554.

The spelling of 81428582 in words is "eighty-one million, four hundred twenty-eight thousand, five hundred eighty-two".