81253442 has 8 divisors (see below), whose sum is σ = 121999500. Its totient is φ = 40586944.

The previous prime is 81253439. The next prime is 81253451. The reversal of 81253442 is 24435218.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 80982001 + 271441 = 8999^2 + 521^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 17267 + ... + 21462.

Almost surely, 2^81253442 is an apocalyptic number.

81253442 is a deficient number, since it is larger than the sum of its proper divisors (40746058).

81253442 is a wasteful number, since it uses less digits than its factorization.

81253442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39780.

The product of its digits is 7680, while the sum is 29.

The square root of 81253442 is about 9014.0691144455. The cubic root of 81253442 is about 433.1256686764.

The spelling of 81253442 in words is "eighty-one million, two hundred fifty-three thousand, four hundred forty-two".