1221008069 has 2 divisors, whose sum is σ = 1221008070. Its totient is φ = 1221008068.

The previous prime is 1221007993. The next prime is 1221008123. The reversal of 1221008069 is 9608001221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1014741025 + 206267044 = 31855^2 + 14362^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221008069 - 2²⁸ = 952572613 is a prime.

It is a super-2 number, since 2×1221008069² = 2981721409126217522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221008869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610504034 + 610504035.

It is an arithmetic number, because the mean of its divisors is an integer number (610504035).

Almost surely, 2^1221008069 is an apocalyptic number.

It is an amenable number.

1221008069 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221008069 is an equidigital number, since it uses as much as digits as its factorization.

1221008069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 1221008069 is about 34942.9258792105. The cubic root of 1221008069 is about 1068.8239528686.

The spelling of 1221008069 in words is "one billion, two hundred twenty-one million, eight thousand, sixty-nine".