87561689 has 2 divisors, whose sum is σ = 87561690. Its totient is φ = 87561688.

The previous prime is 87561653. The next prime is 87561731. The reversal of 87561689 is 98616578.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75255625 + 12306064 = 8675^2 + 3508^2 .

It is a cyclic number.

It is not a de Polignac number, because 87561689 - 2²⁴ = 70784473 is a prime.

It is not a weakly prime, because it can be changed into another prime (87561629) 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, 43780844 + 43780845.

It is an arithmetic number, because the mean of its divisors is an integer number (43780845).

Almost surely, 2^87561689 is an apocalyptic number.

It is an amenable number.

87561689 is a deficient number, since it is larger than the sum of its proper divisors (1).

87561689 is an equidigital number, since it uses as much as digits as its factorization.

87561689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 50.

The square root of 87561689 is about 9357.4403017064. The cubic root of 87561689 is about 444.0563076195.

The spelling of 87561689 in words is "eighty-seven million, five hundred sixty-one thousand, six hundred eighty-nine".