81124085 has 16 divisors (see below), whose sum is σ = 117801216. Its totient is φ = 52355328.

The previous prime is 81124067. The next prime is 81124157. The reversal of 81124085 is 58042118.

It is a cyclic number.

It is not a de Polignac number, because 81124085 - 2¹⁰ = 81123061 is a prime.

It is a super-2 number, since 2×81124085² = 13162234334174450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67577 + ... + 68766.

It is an arithmetic number, because the mean of its divisors is an integer number (7362576).

Almost surely, 2^81124085 is an apocalyptic number.

81124085 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81124085 is a deficient number, since it is larger than the sum of its proper divisors (36677131).

81124085 is a wasteful number, since it uses less digits than its factorization.

81124085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136372.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 81124085 is about 9006.8909730273. The cubic root of 81124085 is about 432.8956985380.

The spelling of 81124085 in words is "eighty-one million, one hundred twenty-four thousand, eighty-five".