81361123 has 2 divisors, whose sum is σ = 81361124. Its totient is φ = 81361122.

The previous prime is 81361079. The next prime is 81361127. The reversal of 81361123 is 32116318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81361123 - 2⁹ = 81360611 is a prime.

It is a super-2 number, since 2×81361123² = 13239264671642258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81361127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40680561 + 40680562.

It is an arithmetic number, because the mean of its divisors is an integer number (40680562).

Almost surely, 2^81361123 is an apocalyptic number.

81361123 is a deficient number, since it is larger than the sum of its proper divisors (1).

81361123 is an equidigital number, since it uses as much as digits as its factorization.

81361123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 81361123 is about 9020.0400775163. The cubic root of 81361123 is about 433.3169172611.

The spelling of 81361123 in words is "eighty-one million, three hundred sixty-one thousand, one hundred twenty-three".