221043643 has 2 divisors, whose sum is σ = 221043644. Its totient is φ = 221043642.

The previous prime is 221043637. The next prime is 221043649. The reversal of 221043643 is 346340122.

It is a balanced prime because it is at equal distance from previous prime (221043637) and next prime (221043649).

It is a cyclic number.

It is not a de Polignac number, because 221043643 - 2⁵ = 221043611 is a prime.

It is a super-2 number, since 2×221043643² = 97720584221422898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221043649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110521821 + 110521822.

It is an arithmetic number, because the mean of its divisors is an integer number (110521822).

Almost surely, 2^221043643 is an apocalyptic number.

221043643 is a deficient number, since it is larger than the sum of its proper divisors (1).

221043643 is an equidigital number, since it uses as much as digits as its factorization.

221043643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 221043643 is about 14867.5365477943. The cubic root of 221043643 is about 604.6341553402.

Adding to 221043643 its reverse (346340122), we get a palindrome (567383765).

The spelling of 221043643 in words is "two hundred twenty-one million, forty-three thousand, six hundred forty-three".