221028047 has 16 divisors (see below), whose sum is σ = 236273664. Its totient is φ = 206388000.

The previous prime is 221028019. The next prime is 221028061. The reversal of 221028047 is 740820122.

It is a cyclic number.

It is not a de Polignac number, because 221028047 - 2⁸ = 221027791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221028547) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 149522 + ... + 150992.

It is an arithmetic number, because the mean of its divisors is an integer number (14767104).

Almost surely, 2^221028047 is an apocalyptic number.

221028047 is a deficient number, since it is larger than the sum of its proper divisors (15245617).

221028047 is a wasteful number, since it uses less digits than its factorization.

221028047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1670.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 221028047 is about 14867.0120400839. The cubic root of 221028047 is about 604.6199347758.

Adding to 221028047 its reverse (740820122), we get a palindrome (961848169).

The spelling of 221028047 in words is "two hundred twenty-one million, twenty-eight thousand, forty-seven".