1018647221 has 2 divisors, whose sum is σ = 1018647222. Its totient is φ = 1018647220.

The previous prime is 1018647193. The next prime is 1018647239. The reversal of 1018647221 is 1227468101.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 658179025 + 360468196 = 25655^2 + 18986^2 .

It is an emirp because it is prime and its reverse (1227468101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1018647221 - 2¹⁰ = 1018646197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1018647271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 509323610 + 509323611.

It is an arithmetic number, because the mean of its divisors is an integer number (509323611).

Almost surely, 2^1018647221 is an apocalyptic number.

It is an amenable number.

1018647221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1018647221 is an equidigital number, since it uses as much as digits as its factorization.

1018647221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 1018647221 is about 31916.2532418829. The cubic root of 1018647221 is about 1006.1775002432.

The spelling of 1018647221 in words is "one billion, eighteen million, six hundred forty-seven thousand, two hundred twenty-one".