81242518 has 16 divisors (see below), whose sum is σ = 146603520. Its totient is φ = 32985576.

The previous prime is 81242489. The next prime is 81242519. The reversal of 81242518 is 81524218.

It is a self number, because there is not a number n which added to its sum of digits gives 81242518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81242519) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152446 + ... + 152977.

It is an arithmetic number, because the mean of its divisors is an integer number (9162720).

Almost surely, 2^81242518 is an apocalyptic number.

81242518 is a deficient number, since it is larger than the sum of its proper divisors (65361002).

81242518 is a wasteful number, since it uses less digits than its factorization.

81242518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305451.

The product of its digits is 5120, while the sum is 31.

The square root of 81242518 is about 9013.4631524182. The cubic root of 81242518 is about 433.1062574911.

The spelling of 81242518 in words is "eighty-one million, two hundred forty-two thousand, five hundred eighteen".