221221097 has 2 divisors, whose sum is σ = 221221098. Its totient is φ = 221221096.

The previous prime is 221221087. The next prime is 221221127. The reversal of 221221097 is 790122122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 215972416 + 5248681 = 14696^2 + 2291^2 .

It is a cyclic number.

It is not a de Polignac number, because 221221097 - 2⁴ = 221221081 is a prime.

It is not a weakly prime, because it can be changed into another prime (221221037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610548 + 110610549.

It is an arithmetic number, because the mean of its divisors is an integer number (110610549).

Almost surely, 2^221221097 is an apocalyptic number.

It is an amenable number.

221221097 is a deficient number, since it is larger than the sum of its proper divisors (1).

221221097 is an equidigital number, since it uses as much as digits as its factorization.

221221097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 221221097 is about 14873.5031851948. The cubic root of 221221097 is about 604.7959123106.

The spelling of 221221097 in words is "two hundred twenty-one million, two hundred twenty-one thousand, ninety-seven".