1008191221 has 2 divisors, whose sum is σ = 1008191222. Its totient is φ = 1008191220.

The previous prime is 1008191183. The next prime is 1008191227. The reversal of 1008191221 is 1221918001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 986902225 + 21288996 = 31415^2 + 4614^2 .

It is a cyclic number.

It is not a de Polignac number, because 1008191221 - 2⁹ = 1008190709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1008191227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 504095610 + 504095611.

It is an arithmetic number, because the mean of its divisors is an integer number (504095611).

Almost surely, 2^1008191221 is an apocalyptic number.

It is an amenable number.

1008191221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1008191221 is an equidigital number, since it uses as much as digits as its factorization.

1008191221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 25.

The square root of 1008191221 is about 31752.0270376554. The cubic root of 1008191221 is about 1002.7229856193.

The spelling of 1008191221 in words is "one billion, eight million, one hundred ninety-one thousand, two hundred twenty-one".