87686781 has 32 divisors (see below), whose sum is σ = 147802368. Its totient is φ = 44997120.

The previous prime is 87686779. The next prime is 87686791. The reversal of 87686781 is 18768678.

It is not a de Polignac number, because 87686781 - 2¹ = 87686779 is a prime.

It is a super-2 number, since 2×87686781² = 15377943124283922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87686791) 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 31 ways as a sum of consecutive naturals, for example, 5761 + ... + 14441.

It is an arithmetic number, because the mean of its divisors is an integer number (4618824).

Almost surely, 2^87686781 is an apocalyptic number.

It is an amenable number.

87686781 is a deficient number, since it is larger than the sum of its proper divisors (60115587).

87686781 is a wasteful number, since it uses less digits than its factorization.

87686781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8741.

The product of its digits is 903168, while the sum is 51.

The square root of 87686781 is about 9364.1220090300. The cubic root of 87686781 is about 444.2676689316.

The spelling of 87686781 in words is "eighty-seven million, six hundred eighty-six thousand, seven hundred eighty-one".