1988621198 has 4 divisors (see below), whose sum is σ = 2982931800. Its totient is φ = 994310598.

The previous prime is 1988621197. The next prime is 1988621207. The reversal of 1988621198 is 8911268891.

It is a happy number.

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

It is a super-2 number, since 2×1988621198² = 7909228538269910408, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988621191) 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 as a sum of consecutive naturals, namely, 497155298 + ... + 497155301.

It is an arithmetic number, because the mean of its divisors is an integer number (745732950).

Almost surely, 2^1988621198 is an apocalyptic number.

1988621198 is a deficient number, since it is larger than the sum of its proper divisors (994310602).

1988621198 is an equidigital number, since it uses as much as digits as its factorization.

1988621198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994310601.

The product of its digits is 497664, while the sum is 53.

The square root of 1988621198 is about 44593.9592097405. The cubic root of 1988621198 is about 1257.5271054080.

The spelling of 1988621198 in words is "one billion, nine hundred eighty-eight million, six hundred twenty-one thousand, one hundred ninety-eight".