1366122221 has 4 divisors (see below), whose sum is σ = 1370949792. Its totient is φ = 1361294652.

The previous prime is 1366122209. The next prime is 1366122253. The reversal of 1366122221 is 1222216631.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1222216631 = 127 ⋅9623753.

It is a cyclic number.

It is not a de Polignac number, because 1366122221 - 2¹⁴ = 1366105837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1366122271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2413361 + ... + 2413926.

It is an arithmetic number, because the mean of its divisors is an integer number (342737448).

Almost surely, 2^1366122221 is an apocalyptic number.

It is an amenable number.

1366122221 is a deficient number, since it is larger than the sum of its proper divisors (4827571).

1366122221 is an equidigital number, since it uses as much as digits as its factorization.

1366122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4827570.

The product of its digits is 1728, while the sum is 26.

The square root of 1366122221 is about 36961.0906359647. The cubic root of 1366122221 is about 1109.5916635090.

Adding to 1366122221 its reverse (1222216631), we get a palindrome (2588338852).

The spelling of 1366122221 in words is "one billion, three hundred sixty-six million, one hundred twenty-two thousand, two hundred twenty-one".