81718525 has 36 divisors (see below), whose sum is σ = 124114080. Its totient is φ = 53071200.

The previous prime is 81718519. The next prime is 81718529. The reversal of 81718525 is 52581718.

It is not a de Polignac number, because 81718525 - 2¹¹ = 81716477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81718529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 21520 + ... + 25030.

Almost surely, 2^81718525 is an apocalyptic number.

It is an amenable number.

81718525 is a deficient number, since it is larger than the sum of its proper divisors (42395555).

81718525 is a wasteful number, since it uses less digits than its factorization.

81718525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3554 (or 3542 counting only the distinct ones).

The product of its digits is 22400, while the sum is 37.

The square root of 81718525 is about 9039.8299209664. The cubic root of 81718525 is about 433.9504799552.

The spelling of 81718525 in words is "eighty-one million, seven hundred eighteen thousand, five hundred twenty-five".