81938111 has 2 divisors, whose sum is σ = 81938112. Its totient is φ = 81938110.

The previous prime is 81938081. The next prime is 81938141. The reversal of 81938111 is 11183918.

It is a balanced prime because it is at equal distance from previous prime (81938081) and next prime (81938141).

It is a cyclic number.

It is not a de Polignac number, because 81938111 - 2²² = 77743807 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81938141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40969055 + 40969056.

It is an arithmetic number, because the mean of its divisors is an integer number (40969056).

Almost surely, 2^81938111 is an apocalyptic number.

81938111 is a deficient number, since it is larger than the sum of its proper divisors (1).

81938111 is an equidigital number, since it uses as much as digits as its factorization.

81938111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 32.

The square root of 81938111 is about 9051.9672447485. The cubic root of 81938111 is about 434.3388220374.

The spelling of 81938111 in words is "eighty-one million, nine hundred thirty-eight thousand, one hundred eleven".