988661 has 2 divisors, whose sum is σ = 988662. Its totient is φ = 988660.

The previous prime is 988651. The next prime is 988681. The reversal of 988661 is 166889.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 988036 + 625 = 994^2 + 25^2 .

It is a cyclic number.

It is not a de Polignac number, because 988661 - 2¹⁴ = 972277 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (988651) 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, 494330 + 494331.

It is an arithmetic number, because the mean of its divisors is an integer number (494331).

2⁹⁸⁸⁶⁶¹ is an apocalyptic number.

It is an amenable number.

988661 is a deficient number, since it is larger than the sum of its proper divisors (1).

988661 is an equidigital number, since it uses as much as digits as its factorization.

988661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 38.

The square root of 988661 is about 994.3143366159. The cubic root of 988661 is about 99.6205956774.

The spelling of 988661 in words is "nine hundred eighty-eight thousand, six hundred sixty-one".