1355222021 has 2 divisors, whose sum is σ = 1355222022. Its totient is φ = 1355222020.

The previous prime is 1355221999. The next prime is 1355222053. The reversal of 1355222021 is 1202225531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 991557121 + 363664900 = 31489^2 + 19070^2 .

It is a cyclic number.

It is not a de Polignac number, because 1355222021 - 2³⁰ = 281480197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1355222081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 677611010 + 677611011.

It is an arithmetic number, because the mean of its divisors is an integer number (677611011).

Almost surely, 2^1355222021 is an apocalyptic number.

It is an amenable number.

1355222021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1355222021 is an equidigital number, since it uses as much as digits as its factorization.

1355222021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 1355222021 is about 36813.3402586617. The cubic root of 1355222021 is about 1106.6326597891.

Adding to 1355222021 its reverse (1202225531), we get a palindrome (2557447552).

The spelling of 1355222021 in words is "one billion, three hundred fifty-five million, two hundred twenty-two thousand, twenty-one".