81421411 has 2 divisors, whose sum is σ = 81421412. Its totient is φ = 81421410.

The previous prime is 81421393. The next prime is 81421421. The reversal of 81421411 is 11412418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81421411 - 2¹¹ = 81419363 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81421421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40710705 + 40710706.

It is an arithmetic number, because the mean of its divisors is an integer number (40710706).

Almost surely, 2^81421411 is an apocalyptic number.

81421411 is a deficient number, since it is larger than the sum of its proper divisors (1).

81421411 is an equidigital number, since it uses as much as digits as its factorization.

81421411 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 256, while the sum is 22.

The square root of 81421411 is about 9023.3813506911. The cubic root of 81421411 is about 433.4239190636.

Adding to 81421411 its reverse (11412418), we get a palindrome (92833829).

The spelling of 81421411 in words is "eighty-one million, four hundred twenty-one thousand, four hundred eleven".