81353242 has 4 divisors (see below), whose sum is σ = 122029866. Its totient is φ = 40676620.

The previous prime is 81353201. The next prime is 81353243. The reversal of 81353242 is 24235318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24235318 = 2 ⋅12117659.

It can be written as a sum of positive squares in only one way, i.e., 81018001 + 335241 = 9001^2 + 579^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81353242.

It is not an unprimeable number, because it can be changed into a prime (81353243) 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 as a sum of consecutive naturals, namely, 20338309 + ... + 20338312.

Almost surely, 2^81353242 is an apocalyptic number.

81353242 is a deficient number, since it is larger than the sum of its proper divisors (40676624).

81353242 is a wasteful number, since it uses less digits than its factorization.

81353242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40676623.

The product of its digits is 5760, while the sum is 28.

The square root of 81353242 is about 9019.6032063500. The cubic root of 81353242 is about 433.3029258085.

The spelling of 81353242 in words is "eighty-one million, three hundred fifty-three thousand, two hundred forty-two".