81425727 has 12 divisors (see below), whose sum is σ = 122728944. Its totient is φ = 51923520.

The previous prime is 81425719. The next prime is 81425731. The reversal of 81425727 is 72752418.

81425727 is a `hidden beast` number, since 81 + 4 + 2 + 572 + 7 = 666.

It is not a de Polignac number, because 81425727 - 2³ = 81425719 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 81425691 and 81425700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81425717) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 196474 + ... + 196887.

It is an arithmetic number, because the mean of its divisors is an integer number (10227412).

Almost surely, 2^81425727 is an apocalyptic number.

81425727 is a deficient number, since it is larger than the sum of its proper divisors (41303217).

81425727 is a wasteful number, since it uses less digits than its factorization.

81425727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393390 (or 393387 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 81425727 is about 9023.6205039884. The cubic root of 81425727 is about 433.4315772645.

The spelling of 81425727 in words is "eighty-one million, four hundred twenty-five thousand, seven hundred twenty-seven".