221729489 has 2 divisors, whose sum is σ = 221729490. Its totient is φ = 221729488.

The previous prime is 221729483. The next prime is 221729491. The reversal of 221729489 is 984927122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158256400 + 63473089 = 12580^2 + 7967^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221729489 is a prime.

It is a super-2 number, since 2×221729489² = 98327932584402242, which contains 22 as substring.

Together with 221729491, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221729483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110864744 + 110864745.

It is an arithmetic number, because the mean of its divisors is an integer number (110864745).

Almost surely, 2^221729489 is an apocalyptic number.

It is an amenable number.

221729489 is a deficient number, since it is larger than the sum of its proper divisors (1).

221729489 is an equidigital number, since it uses as much as digits as its factorization.

221729489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 221729489 is about 14890.5839039307. The cubic root of 221729489 is about 605.2588551481.

The spelling of 221729489 in words is "two hundred twenty-one million, seven hundred twenty-nine thousand, four hundred eighty-nine".