87021218 has 4 divisors (see below), whose sum is σ = 130531830. Its totient is φ = 43510608.

The previous prime is 87021211. The next prime is 87021223. The reversal of 87021218 is 81212078.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81212078 = 2 ⋅40606039.

It can be written as a sum of positive squares in only one way, i.e., 58323769 + 28697449 = 7637^2 + 5357^2 .

It is not an unprimeable number, because it can be changed into a prime (87021211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21755303 + ... + 21755306.

Almost surely, 2^87021218 is an apocalyptic number.

87021218 is a deficient number, since it is larger than the sum of its proper divisors (43510612).

87021218 is a wasteful number, since it uses less digits than its factorization.

87021218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43510611.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 87021218 is about 9328.5163879365. The cubic root of 87021218 is about 443.1407814515.

The spelling of 87021218 in words is "eighty-seven million, twenty-one thousand, two hundred eighteen".