81337589 has 6 divisors (see below), whose sum is σ = 83107254. Its totient is φ = 79604840.

The previous prime is 81337567. The next prime is 81337601. The reversal of 81337589 is 98573318.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 63840100 + 17497489 = 7990^2 + 4183^2 .

It is not a de Polignac number, because 81337589 - 2¹² = 81333493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81337519) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16202 + ... + 20619.

It is an arithmetic number, because the mean of its divisors is an integer number (13851209).

Almost surely, 2^81337589 is an apocalyptic number.

It is an amenable number.

81337589 is a deficient number, since it is larger than the sum of its proper divisors (1769665).

81337589 is an equidigital number, since it uses as much as digits as its factorization.

81337589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36915 (or 36868 counting only the distinct ones).

The product of its digits is 181440, while the sum is 44.

The square root of 81337589 is about 9018.7354435087. The cubic root of 81337589 is about 433.2751337354.

The spelling of 81337589 in words is "eighty-one million, three hundred thirty-seven thousand, five hundred eighty-nine".