81236124 has 18 divisors (see below), whose sum is σ = 205346960. Its totient is φ = 27078696.

The previous prime is 81236123. The next prime is 81236131. The reversal of 81236124 is 42163218.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81236123) 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 in 5 ways as a sum of consecutive naturals, for example, 1128244 + ... + 1128315.

Almost surely, 2^81236124 is an apocalyptic number.

It is an amenable number.

81236124 is an abundant number, since it is smaller than the sum of its proper divisors (124110836).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81236124 is a wasteful number, since it uses less digits than its factorization.

81236124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2256569 (or 2256564 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 81236124 is about 9013.1084538022. The cubic root of 81236124 is about 433.0948949922.

The spelling of 81236124 in words is "eighty-one million, two hundred thirty-six thousand, one hundred twenty-four".