81386487 has 48 divisors (see below), whose sum is σ = 148115968. Its totient is φ = 41912640.

The previous prime is 81386483. The next prime is 81386521. The reversal of 81386487 is 78468318.

It is not a de Polignac number, because 81386487 - 2² = 81386483 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81386483) 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 47 ways as a sum of consecutive naturals, for example, 34062 + ... + 36372.

Almost surely, 2^81386487 is an apocalyptic number.

81386487 is a deficient number, since it is larger than the sum of its proper divisors (66729481).

81386487 is a wasteful number, since it uses less digits than its factorization.

81386487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2380 (or 2377 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 81386487 is about 9021.4459484054. The cubic root of 81386487 is about 433.3619408464.

The spelling of 81386487 in words is "eighty-one million, three hundred eighty-six thousand, four hundred eighty-seven".