221004288 has 150 divisors (see below), whose sum is σ = 668799549. Its totient is φ = 72658944.

The previous prime is 221004269. The next prime is 221004307. The reversal of 221004288 is 882400122.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is an interprime number because it is at equal distance from previous prime (221004269) and next prime (221004307).

It can be written as a sum of positive squares in 2 ways, for example, as 219988224 + 1016064 = 14832^2 + 1008^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=10512.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 3027420 + ... + 3027492.

Almost surely, 2^221004288 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221004288

221004288 is an abundant number, since it is smaller than the sum of its proper divisors (447795261).

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

221004288 is an frugal number, since it uses more digits than its factorization.

221004288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 221004288 is about 14866.2129676660. The cubic root of 221004288 is about 604.5982698333.

Multiplying 221004288 by its product of nonzero digits (2048), we get a square (452616781824 = 672768²).

The spelling of 221004288 in words is "two hundred twenty-one million, four thousand, two hundred eighty-eight".