81222589 has 4 divisors (see below), whose sum is σ = 92825824. Its totient is φ = 69619356.

The previous prime is 81222577. The next prime is 81222619. The reversal of 81222589 is 98522218.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81222589 - 2¹¹ = 81220541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81222529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5801607 + ... + 5801620.

It is an arithmetic number, because the mean of its divisors is an integer number (23206456).

Almost surely, 2^81222589 is an apocalyptic number.

It is an amenable number.

81222589 is a deficient number, since it is larger than the sum of its proper divisors (11603235).

81222589 is a wasteful number, since it uses less digits than its factorization.

81222589 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11603234.

The product of its digits is 23040, while the sum is 37.

The square root of 81222589 is about 9012.3575716901. The cubic root of 81222589 is about 433.0708405662.

The spelling of 81222589 in words is "eighty-one million, two hundred twenty-two thousand, five hundred eighty-nine".