1205137321 has 2 divisors, whose sum is σ = 1205137322. Its totient is φ = 1205137320.

The previous prime is 1205137309. The next prime is 1205137331. The reversal of 1205137321 is 1237315021.

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., 856381696 + 348755625 = 29264^2 + 18675^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205137321 - 2²¹ = 1203040169 is a prime.

It is not a weakly prime, because it can be changed into another prime (1205137331) 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 as a sum of consecutive naturals, namely, 602568660 + 602568661.

It is an arithmetic number, because the mean of its divisors is an integer number (602568661).

Almost surely, 2^1205137321 is an apocalyptic number.

It is an amenable number.

1205137321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205137321 is an equidigital number, since it uses as much as digits as its factorization.

1205137321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 1205137321 is about 34715.0878005515. The cubic root of 1205137321 is about 1064.1728597858.

The spelling of 1205137321 in words is "one billion, two hundred five million, one hundred thirty-seven thousand, three hundred twenty-one".