87566421 has 16 divisors (see below), whose sum is σ = 123112640. Its totient is φ = 55209600.

The previous prime is 87566419. The next prime is 87566429. The reversal of 87566421 is 12466578.

It is not a de Polignac number, because 87566421 - 2¹ = 87566419 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 87566421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87566429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47721 + ... + 49521.

It is an arithmetic number, because the mean of its divisors is an integer number (7694540).

Almost surely, 2^87566421 is an apocalyptic number.

87566421 is the 5403-rd octagonal number.

It is an amenable number.

87566421 is a deficient number, since it is larger than the sum of its proper divisors (35546219).

87566421 is a wasteful number, since it uses less digits than its factorization.

87566421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2676.

The product of its digits is 80640, while the sum is 39.

The square root of 87566421 is about 9357.6931452148. The cubic root of 87566421 is about 444.0643066909.

The spelling of 87566421 in words is "eighty-seven million, five hundred sixty-six thousand, four hundred twenty-one".