221243004 has 36 divisors (see below), whose sum is σ = 559704600. Its totient is φ = 73688160.

The previous prime is 221242999. The next prime is 221243021. The reversal of 221243004 is 400342122.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85522 + ... + 88070.

It is an arithmetic number, because the mean of its divisors is an integer number (15547350).

Almost surely, 2^221243004 is an apocalyptic number.

It is an amenable number.

221243004 is an abundant number, since it is smaller than the sum of its proper divisors (338461596).

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

221243004 is a wasteful number, since it uses less digits than its factorization.

221243004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4970 (or 4965 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 221243004 is about 14874.2396108171. The cubic root of 221243004 is about 604.8158754861.

Adding to 221243004 its reverse (400342122), we get a palindrome (621585126).

The spelling of 221243004 in words is "two hundred twenty-one million, two hundred forty-three thousand, four".