221998004 has 6 divisors (see below), whose sum is σ = 388496514. Its totient is φ = 110999000.

The previous prime is 221997991. The next prime is 221998027. The reversal of 221998004 is 400899122.

It can be written as a sum of positive squares in only one way, i.e., 220581904 + 1416100 = 14852^2 + 1190^2 .

It is a super-2 number, since 2×221998004² = 98566227559968032, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27749747 + ... + 27749754.

It is an arithmetic number, because the mean of its divisors is an integer number (64749419).

Almost surely, 2^221998004 is an apocalyptic number.

It is an amenable number.

221998004 is a deficient number, since it is larger than the sum of its proper divisors (166498510).

221998004 is a wasteful number, since it uses less digits than its factorization.

221998004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55499505 (or 55499503 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 221998004 is about 14899.5974442265. The cubic root of 221998004 is about 605.5030799493.

It can be divided in two parts, 22199 and 8004, that added together give a palindrome (30203).

The spelling of 221998004 in words is "two hundred twenty-one million, nine hundred ninety-eight thousand, four".