987913561 has 2 divisors, whose sum is σ = 987913562. Its totient is φ = 987913560.

The previous prime is 987913547. The next prime is 987913601. The reversal of 987913561 is 165319789.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 791353161 + 196560400 = 28131^2 + 14020^2 .

It is a cyclic number.

It is not a de Polignac number, because 987913561 - 2²⁵ = 954359129 is a prime.

It is not a weakly prime, because it can be changed into another prime (987919561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493956780 + 493956781.

It is an arithmetic number, because the mean of its divisors is an integer number (493956781).

Almost surely, 2^987913561 is an apocalyptic number.

It is an amenable number.

987913561 is a deficient number, since it is larger than the sum of its proper divisors (1).

987913561 is an equidigital number, since it uses as much as digits as its factorization.

987913561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 408240, while the sum is 49.

The square root of 987913561 is about 31431.0922654622. The cubic root of 987913561 is about 995.9548457914.

The spelling of 987913561 in words is "nine hundred eighty-seven million, nine hundred thirteen thousand, five hundred sixty-one".