988591 has 2 divisors, whose sum is σ = 988592. Its totient is φ = 988590.

The previous prime is 988583. The next prime is 988607. The reversal of 988591 is 195889.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 988591 - 2³ = 988583 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (988501) 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, 494295 + 494296.

It is an arithmetic number, because the mean of its divisors is an integer number (494296).

2⁹⁸⁸⁵⁹¹ is an apocalyptic number.

988591 is a deficient number, since it is larger than the sum of its proper divisors (1).

988591 is an equidigital number, since it uses as much as digits as its factorization.

988591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 40.

The square root of 988591 is about 994.2791358567. The cubic root of 988591 is about 99.6182444818.

The spelling of 988591 in words is "nine hundred eighty-eight thousand, five hundred ninety-one".