87218881 has 4 divisors (see below), whose sum is σ = 87242452. Its totient is φ = 87195312.

The previous prime is 87218869. The next prime is 87218899. The reversal of 87218881 is 18881278.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16810000 + 70408881 = 4100^2 + 8391^2 .

It is a cyclic number.

It is not a de Polignac number, because 87218881 - 2¹⁹ = 86694593 is a prime.

It is a super-2 number, since 2×87218881² = 15214266405784322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87218821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4890 + ... + 14083.

It is an arithmetic number, because the mean of its divisors is an integer number (21810613).

Almost surely, 2^87218881 is an apocalyptic number.

It is an amenable number.

87218881 is a deficient number, since it is larger than the sum of its proper divisors (23571).

87218881 is a wasteful number, since it uses less digits than its factorization.

87218881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23570.

The product of its digits is 57344, while the sum is 43.

The square root of 87218881 is about 9339.1049356991. The cubic root of 87218881 is about 443.4760494915.

The spelling of 87218881 in words is "eighty-seven million, two hundred eighteen thousand, eight hundred eighty-one".