1369280021 has 2 divisors, whose sum is σ = 1369280022. Its totient is φ = 1369280020.

The previous prime is 1369280009. The next prime is 1369280027. The reversal of 1369280021 is 1200829631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1280637796 + 88642225 = 35786^2 + 9415^2 .

It is an emirp because it is prime and its reverse (1200829631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1369280021 - 2¹⁰ = 1369278997 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1369280021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1369280027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 684640010 + 684640011.

It is an arithmetic number, because the mean of its divisors is an integer number (684640011).

Almost surely, 2^1369280021 is an apocalyptic number.

It is an amenable number.

1369280021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1369280021 is an equidigital number, since it uses as much as digits as its factorization.

1369280021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 1369280021 is about 37003.7838740851. The cubic root of 1369280021 is about 1110.4459482928.

The spelling of 1369280021 in words is "one billion, three hundred sixty-nine million, two hundred eighty thousand, twenty-one".