81943325 has 12 divisors (see below), whose sum is σ = 103773120. Its totient is φ = 64158960.

The previous prime is 81943307. The next prime is 81943331. The reversal of 81943325 is 52334918.

It is a de Polignac number, because none of the positive numbers 2^k-81943325 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33695 + ... + 36044.

It is an arithmetic number, because the mean of its divisors is an integer number (8647760).

Almost surely, 2^81943325 is an apocalyptic number.

It is an amenable number.

81943325 is a deficient number, since it is larger than the sum of its proper divisors (21829795).

81943325 is a wasteful number, since it uses less digits than its factorization.

81943325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69796 (or 69791 counting only the distinct ones).

The product of its digits is 25920, while the sum is 35.

The square root of 81943325 is about 9052.2552438605. The cubic root of 81943325 is about 434.3480346596.

It can be divided in two parts, 819 and 43325, that added together give a palindrome (44144).

The spelling of 81943325 in words is "eighty-one million, nine hundred forty-three thousand, three hundred twenty-five".