87218261 has 8 divisors (see below), whose sum is σ = 94052280. Its totient is φ = 80402112.

The previous prime is 87218249. The next prime is 87218267. The reversal of 87218261 is 16281278.

It can be written as a sum of positive squares in 4 ways, for example, as 3587236 + 83631025 = 1894^2 + 9145^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 87218261 - 2²² = 83023957 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 (87218267) 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 7 ways as a sum of consecutive naturals, for example, 6731 + ... + 14823.

It is an arithmetic number, because the mean of its divisors is an integer number (11756535).

Almost surely, 2^87218261 is an apocalyptic number.

It is an amenable number.

87218261 is a deficient number, since it is larger than the sum of its proper divisors (6834019).

87218261 is a wasteful number, since it uses less digits than its factorization.

87218261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8935.

The product of its digits is 10752, while the sum is 35.

The square root of 87218261 is about 9339.0717418810. The cubic root of 87218261 is about 443.4749986648.

The spelling of 87218261 in words is "eighty-seven million, two hundred eighteen thousand, two hundred sixty-one".