81235042 has 48 divisors (see below), whose sum is σ = 146562048. Its totient is φ = 33657120.

The previous prime is 81235031. The next prime is 81235043. The reversal of 81235042 is 24053218.

It is a junction number, because it is equal to n+sod(n) for n = 81234998 and 81235016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81235043) 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 23 ways as a sum of consecutive naturals, for example, 639583 + ... + 639709.

It is an arithmetic number, because the mean of its divisors is an integer number (3053376).

Almost surely, 2^81235042 is an apocalyptic number.

81235042 is a deficient number, since it is larger than the sum of its proper divisors (65327006).

81235042 is a wasteful number, since it uses less digits than its factorization.

81235042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311 (or 304 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 81235042 is about 9013.0484299154. The cubic root of 81235042 is about 433.0929721581.

The spelling of 81235042 in words is "eighty-one million, two hundred thirty-five thousand, forty-two".