81679111 has 2 divisors, whose sum is σ = 81679112. Its totient is φ = 81679110.

The previous prime is 81679063. The next prime is 81679139. The reversal of 81679111 is 11197618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81679111 - 2⁷ = 81678983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81679151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40839555 + 40839556.

It is an arithmetic number, because the mean of its divisors is an integer number (40839556).

Almost surely, 2^81679111 is an apocalyptic number.

81679111 is a deficient number, since it is larger than the sum of its proper divisors (1).

81679111 is an equidigital number, since it uses as much as digits as its factorization.

81679111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 34.

The square root of 81679111 is about 9037.6496391484. The cubic root of 81679111 is about 433.8807019183.

The spelling of 81679111 in words is "eighty-one million, six hundred seventy-nine thousand, one hundred eleven".