1021998 has 16 divisors (see below), whose sum is σ = 2079360. Its totient is φ = 334776.

The previous prime is 1021973. The next prime is 1022011. The reversal of 1021998 is 8991201.

It is an Ulam number.

It is a Curzon number.

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 in 7 ways as a sum of consecutive naturals, for example, 1090 + ... + 1797.

It is an arithmetic number, because the mean of its divisors is an integer number (129960).

2^1021998 is an apocalyptic number.

1021998 is an abundant number, since it is smaller than the sum of its proper divisors (1057362).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1021998 is a wasteful number, since it uses less digits than its factorization.

1021998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2951.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 1021998 is about 1010.9391673093. The cubic root of 1021998 is about 100.7279546287.

The spelling of 1021998 in words is "one million, twenty-one thousand, nine hundred ninety-eight".