81293542 has 16 divisors (see below), whose sum is σ = 133358400. Its totient is φ = 36859240.

The previous prime is 81293539. The next prime is 81293549. The reversal of 81293542 is 24539218.

It is a junction number, because it is equal to n+sod(n) for n = 81293498 and 81293507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81293549) 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 7 ways as a sum of consecutive naturals, for example, 4809 + ... + 13627.

It is an arithmetic number, because the mean of its divisors is an integer number (8334900).

Almost surely, 2^81293542 is an apocalyptic number.

81293542 is a deficient number, since it is larger than the sum of its proper divisors (52064858).

81293542 is a wasteful number, since it uses less digits than its factorization.

81293542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9251.

The product of its digits is 17280, while the sum is 34.

The square root of 81293542 is about 9016.2931407536. The cubic root of 81293542 is about 433.1969086652.

The spelling of 81293542 in words is "eighty-one million, two hundred ninety-three thousand, five hundred forty-two".