87510221 has 2 divisors, whose sum is σ = 87510222. Its totient is φ = 87510220.

The previous prime is 87510211. The next prime is 87510259. The reversal of 87510221 is 12201578.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80802121 + 6708100 = 8989^2 + 2590^2 .

It is a cyclic number.

It is not a de Polignac number, because 87510221 - 2²⁶ = 20401357 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87510211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43755110 + 43755111.

It is an arithmetic number, because the mean of its divisors is an integer number (43755111).

Almost surely, 2^87510221 is an apocalyptic number.

It is an amenable number.

87510221 is a deficient number, since it is larger than the sum of its proper divisors (1).

87510221 is an equidigital number, since it uses as much as digits as its factorization.

87510221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 87510221 is about 9354.6897864119. The cubic root of 87510221 is about 443.9692864207.

Adding to 87510221 its reverse (12201578), we get a palindrome (99711799).

The spelling of 87510221 in words is "eighty-seven million, five hundred ten thousand, two hundred twenty-one".