1821111198 has 16 divisors (see below), whose sum is σ = 3657338256. Its totient is φ = 604517760.

The previous prime is 1821111197. The next prime is 1821111199. The reversal of 1821111198 is 8911111281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1821111197) and next prime (1821111199).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821111197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 628261 + ... + 631152.

It is an arithmetic number, because the mean of its divisors is an integer number (228583641).

Almost surely, 2^1821111198 is an apocalyptic number.

1821111198 is an abundant number, since it is smaller than the sum of its proper divisors (1836227058).

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

1821111198 is a wasteful number, since it uses less digits than its factorization.

1821111198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1259659.

The product of its digits is 1152, while the sum is 33.

The square root of 1821111198 is about 42674.4794695846. The cubic root of 1821111198 is about 1221.1775779545.

The spelling of 1821111198 in words is "one billion, eight hundred twenty-one million, one hundred eleven thousand, one hundred ninety-eight".