998987 has 8 divisors (see below), whose sum is σ = 1097712. Its totient is φ = 901600.

The previous prime is 998983. The next prime is 998989. The reversal of 998987 is 789899.

Added to its reverse (789899) it gives a triangular number (1788886 = T₁₈₉₁).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 998987 - 2² = 998983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (998983) 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 in 7 ways as a sum of consecutive naturals, for example, 1937 + ... + 2397.

It is an arithmetic number, because the mean of its divisors is an integer number (137214).

2⁹⁹⁸⁹⁸⁷ is an apocalyptic number.

998987 is a deficient number, since it is larger than the sum of its proper divisors (98725).

998987 is a wasteful number, since it uses less digits than its factorization.

998987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669.

The product of its digits is 326592, while the sum is 50.

The square root of 998987 is about 999.4933716639. The cubic root of 998987 is about 99.9662219250.

Adding to 998987 its reverse (789899), we get a triangular number (1788886 = T₁₈₉₁).

The spelling of 998987 in words is "nine hundred ninety-eight thousand, nine hundred eighty-seven".