81694525 has 24 divisors (see below), whose sum is σ = 110930400. Its totient is φ = 59188800.

The previous prime is 81694513. The next prime is 81694541. The reversal of 81694525 is 52549618.

It is not a de Polignac number, because 81694525 - 2⁹ = 81694013 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 114871 + ... + 115579.

It is an arithmetic number, because the mean of its divisors is an integer number (4622100).

Almost surely, 2^81694525 is an apocalyptic number.

It is an amenable number.

81694525 is a deficient number, since it is larger than the sum of its proper divisors (29235875).

81694525 is a wasteful number, since it uses less digits than its factorization.

81694525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149 (or 1144 counting only the distinct ones).

The product of its digits is 86400, while the sum is 40.

The square root of 81694525 is about 9038.5023648832. The cubic root of 81694525 is about 433.9079933372.

The spelling of 81694525 in words is "eighty-one million, six hundred ninety-four thousand, five hundred twenty-five".