247289221 has 2 divisors, whose sum is σ = 247289222. Its totient is φ = 247289220.

The previous prime is 247289219. The next prime is 247289243. The reversal of 247289221 is 122982742.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164224225 + 83064996 = 12815^2 + 9114^2 .

It is a cyclic number.

It is not a de Polignac number, because 247289221 - 2¹ = 247289219 is a prime.

It is a super-2 number, since 2×247289221² = 122303917645573682, which contains 22 as substring.

Together with 247289219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247280221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123644610 + 123644611.

It is an arithmetic number, because the mean of its divisors is an integer number (123644611).

Almost surely, 2^247289221 is an apocalyptic number.

It is an amenable number.

247289221 is a deficient number, since it is larger than the sum of its proper divisors (1).

247289221 is an equidigital number, since it uses as much as digits as its factorization.

247289221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 37.

The square root of 247289221 is about 15725.4322993042. The cubic root of 247289221 is about 627.6753337231.

The spelling of 247289221 in words is "two hundred forty-seven million, two hundred eighty-nine thousand, two hundred twenty-one".