81428259 has 16 divisors (see below), whose sum is σ = 122526720. Its totient is φ = 47648160.

The previous prime is 81428239. The next prime is 81428287. The reversal of 81428259 is 95282418.

It is not a de Polignac number, because 81428259 - 2⁹ = 81427747 is a prime.

It is a super-2 number, since 2×81428259² = 13261122727542162, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81428239) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41587 + ... + 43500.

It is an arithmetic number, because the mean of its divisors is an integer number (7657920).

Almost surely, 2^81428259 is an apocalyptic number.

81428259 is a deficient number, since it is larger than the sum of its proper divisors (41098461).

81428259 is a wasteful number, since it uses less digits than its factorization.

81428259 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85130.

The product of its digits is 46080, while the sum is 39.

The square root of 81428259 is about 9023.7608013511. The cubic root of 81428259 is about 433.4360698552.

The spelling of 81428259 in words is "eighty-one million, four hundred twenty-eight thousand, two hundred fifty-nine".