998681 has 2 divisors, whose sum is σ = 998682. Its totient is φ = 998680.

The previous prime is 998653. The next prime is 998687. The reversal of 998681 is 186899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 739600 + 259081 = 860^2 + 509^2 .

It is a cyclic number.

It is not a de Polignac number, because 998681 - 2⁶ = 998617 is a prime.

It is a super-2 number, since 2×998681² = 1994727479522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (998687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499340 + 499341.

It is an arithmetic number, because the mean of its divisors is an integer number (499341).

2⁹⁹⁸⁶⁸¹ is an apocalyptic number.

It is an amenable number.

998681 is a deficient number, since it is larger than the sum of its proper divisors (1).

998681 is an equidigital number, since it uses as much as digits as its factorization.

998681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 41.

The square root of 998681 is about 999.3402823863. The cubic root of 998681 is about 99.9560139885.

The spelling of 998681 in words is "nine hundred ninety-eight thousand, six hundred eighty-one".