81438611 has 2 divisors, whose sum is σ = 81438612. Its totient is φ = 81438610.

The previous prime is 81438593. The next prime is 81438613. The reversal of 81438611 is 11683418.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81438611 - 2²⁶ = 14329747 is a prime.

Together with 81438613, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 12.

It is not a weakly prime, because it can be changed into another prime (81438613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40719305 + 40719306.

It is an arithmetic number, because the mean of its divisors is an integer number (40719306).

Almost surely, 2^81438611 is an apocalyptic number.

81438611 is a deficient number, since it is larger than the sum of its proper divisors (1).

81438611 is an equidigital number, since it uses as much as digits as its factorization.

81438611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 32.

The square root of 81438611 is about 9024.3343798864. The cubic root of 81438611 is about 433.4544366979.

The spelling of 81438611 in words is "eighty-one million, four hundred thirty-eight thousand, six hundred eleven".