221001998 has 8 divisors (see below), whose sum is σ = 378860592. Its totient is φ = 94715136.

The previous prime is 221001967. The next prime is 221002003. The reversal of 221001998 is 899100122.

It is a happy number.

221001998 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7892915 + ... + 7892942.

It is an arithmetic number, because the mean of its divisors is an integer number (47357574).

Almost surely, 2^221001998 is an apocalyptic number.

221001998 is a deficient number, since it is larger than the sum of its proper divisors (157858594).

221001998 is a wasteful number, since it uses less digits than its factorization.

221001998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15785866.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 221001998 is about 14866.1359471787. The cubic root of 221001998 is about 604.5961815860.

The spelling of 221001998 in words is "two hundred twenty-one million, one thousand, nine hundred ninety-eight".