12121998 has 32 divisors (see below), whose sum is σ = 27815424. Its totient is φ = 3449952.

The previous prime is 12121987. The next prime is 12122009. The reversal of 12121998 is 89912121.

It is an interprime number because it is at equal distance from previous prime (12121987) and next prime (12122009).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16311 + ... + 17037.

It is an arithmetic number, because the mean of its divisors is an integer number (869232).

Almost surely, 2^12121998 is an apocalyptic number.

12121998 is an abundant number, since it is smaller than the sum of its proper divisors (15693426).

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

12121998 is a wasteful number, since it uses less digits than its factorization.

12121998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136.

The product of its digits is 2592, while the sum is 33.

The square root of 12121998 is about 3481.6659805329. The cubic root of 12121998 is about 229.7160831937.

The spelling of 12121998 in words is "twelve million, one hundred twenty-one thousand, nine hundred ninety-eight".