81006487 has 4 divisors (see below), whose sum is σ = 81390616. Its totient is φ = 80622360.

The previous prime is 81006463. The next prime is 81006491. The reversal of 81006487 is 78460018.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81006487 - 2¹⁵ = 80973719 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81006187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191748 + ... + 192169.

It is an arithmetic number, because the mean of its divisors is an integer number (20347654).

Almost surely, 2^81006487 is an apocalyptic number.

81006487 is a deficient number, since it is larger than the sum of its proper divisors (384129).

81006487 is a wasteful number, since it uses less digits than its factorization.

81006487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384128.

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 81006487 is about 9000.3603816736. The cubic root of 81006487 is about 432.6864212443.

The spelling of 81006487 in words is "eighty-one million, six thousand, four hundred eighty-seven".