81530889 has 12 divisors (see below), whose sum is σ = 119489328. Its totient is φ = 49412440.

The previous prime is 81530873. The next prime is 81530951. The reversal of 81530889 is 98803518.

It is not a de Polignac number, because 81530889 - 2⁴ = 81530873 is a prime.

It is a super-2 number, since 2×81530889² = 13294571722260642, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81530889.

It is not an unprimeable number, because it can be changed into a prime (81530809) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 111939 + ... + 112664.

It is an arithmetic number, because the mean of its divisors is an integer number (9957444).

Almost surely, 2^81530889 is an apocalyptic number.

It is an amenable number.

81530889 is a deficient number, since it is larger than the sum of its proper divisors (37958439).

81530889 is a wasteful number, since it uses less digits than its factorization.

81530889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224628 (or 224617 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 42.

The square root of 81530889 is about 9029.4456640483. The cubic root of 81530889 is about 433.6180904823.

The spelling of 81530889 in words is "eighty-one million, five hundred thirty thousand, eight hundred eighty-nine".