87705521 has 2 divisors, whose sum is σ = 87705522. Its totient is φ = 87705520.

The previous prime is 87705511. The next prime is 87705559. The reversal of 87705521 is 12550778.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87684496 + 21025 = 9364^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 87705521 - 2¹⁴ = 87689137 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87705511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43852760 + 43852761.

It is an arithmetic number, because the mean of its divisors is an integer number (43852761).

Almost surely, 2^87705521 is an apocalyptic number.

It is an amenable number.

87705521 is a deficient number, since it is larger than the sum of its proper divisors (1).

87705521 is an equidigital number, since it uses as much as digits as its factorization.

87705521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19600, while the sum is 35.

The square root of 87705521 is about 9365.1225832874. The cubic root of 87705521 is about 444.2993155986.

The spelling of 87705521 in words is "eighty-seven million, seven hundred five thousand, five hundred twenty-one".