1217998 has 4 divisors (see below), whose sum is σ = 1827000. Its totient is φ = 608998.

The previous prime is 1217989. The next prime is 1218017. The reversal of 1217998 is 8997121.

It is a semiprime because it is the product of two primes.

It is a nialpdrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304498 + ... + 304501.

It is an arithmetic number, because the mean of its divisors is an integer number (456750).

2^1217998 is an apocalyptic number.

1217998 is a deficient number, since it is larger than the sum of its proper divisors (609002).

1217998 is an equidigital number, since it uses as much as digits as its factorization.

1217998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609001.

The product of its digits is 9072, while the sum is 37.

The square root of 1217998 is about 1103.6294668049. The cubic root of 1217998 is about 106.7944930226.

The spelling of 1217998 in words is "one million, two hundred seventeen thousand, nine hundred ninety-eight".