87897221 has 2 divisors, whose sum is σ = 87897222. Its totient is φ = 87897220.

The previous prime is 87897181. The next prime is 87897239. The reversal of 87897221 is 12279878.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87422500 + 474721 = 9350^2 + 689^2 .

It is a cyclic number.

It is not a de Polignac number, because 87897221 - 2¹⁸ = 87635077 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 (87897241) 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 as a sum of consecutive naturals, namely, 43948610 + 43948611.

It is an arithmetic number, because the mean of its divisors is an integer number (43948611).

Almost surely, 2^87897221 is an apocalyptic number.

It is an amenable number.

87897221 is a deficient number, since it is larger than the sum of its proper divisors (1).

87897221 is an equidigital number, since it uses as much as digits as its factorization.

87897221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 44.

The square root of 87897221 is about 9375.3517800667. The cubic root of 87897221 is about 444.6227851620.

The spelling of 87897221 in words is "eighty-seven million, eight hundred ninety-seven thousand, two hundred twenty-one".