81925239 has 8 divisors (see below), whose sum is σ = 119164032. Its totient is φ = 49651640.

The previous prime is 81925237. The next prime is 81925247. The reversal of 81925239 is 93252918.

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

It is a cyclic number.

It is not a de Polignac number, because 81925239 - 2¹ = 81925237 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81925197 and 81925206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81925237) 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, 1241259 + ... + 1241324.

It is an arithmetic number, because the mean of its divisors is an integer number (14895504).

Almost surely, 2^81925239 is an apocalyptic number.

81925239 is a deficient number, since it is larger than the sum of its proper divisors (37238793).

81925239 is a wasteful number, since it uses less digits than its factorization.

81925239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2482597.

The product of its digits is 38880, while the sum is 39.

The square root of 81925239 is about 9051.2562111565. The cubic root of 81925239 is about 434.3160768132.

It can be divided in two parts, 8192 and 5239, that added together give a palindrome (13431).

The spelling of 81925239 in words is "eighty-one million, nine hundred twenty-five thousand, two hundred thirty-nine".