87563221 has 4 divisors (see below), whose sum is σ = 87587244. Its totient is φ = 87539200.

The previous prime is 87563183. The next prime is 87563227. The reversal of 87563221 is 12236578.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12236578 = 2 ⋅6118289.

It can be written as a sum of positive squares in 2 ways, for example, as 45495025 + 42068196 = 6745^2 + 6486^2 .

It is a cyclic number.

It is not a de Polignac number, because 87563221 - 2¹⁹ = 87038933 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 (87563227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5290 + ... + 14251.

It is an arithmetic number, because the mean of its divisors is an integer number (21896811).

Almost surely, 2^87563221 is an apocalyptic number.

It is an amenable number.

87563221 is a deficient number, since it is larger than the sum of its proper divisors (24023).

87563221 is a wasteful number, since it uses less digits than its factorization.

87563221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24022.

The product of its digits is 20160, while the sum is 34.

The square root of 87563221 is about 9357.5221613416. The cubic root of 87563221 is about 444.0588973758.

Adding to 87563221 its reverse (12236578), we get a palindrome (99799799).

The spelling of 87563221 in words is "eighty-seven million, five hundred sixty-three thousand, two hundred twenty-one".