1331203121 has 2 divisors, whose sum is σ = 1331203122. Its totient is φ = 1331203120.

The previous prime is 1331203109. The next prime is 1331203127. The reversal of 1331203121 is 1213021331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1288810000 + 42393121 = 35900^2 + 6511^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1331203121 is a prime.

It is a super-3 number, since 3×1331203121³ (a number of 28 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1331203121.

It is not a weakly prime, because it can be changed into another prime (1331203127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665601560 + 665601561.

It is an arithmetic number, because the mean of its divisors is an integer number (665601561).

Almost surely, 2^1331203121 is an apocalyptic number.

It is an amenable number.

1331203121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331203121 is an equidigital number, since it uses as much as digits as its factorization.

1331203121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1331203121 is about 36485.6563734298. The cubic root of 1331203121 is about 1100.0559533521.

Adding to 1331203121 its reverse (1213021331), we get a palindrome (2544224452).

The spelling of 1331203121 in words is "one billion, three hundred thirty-one million, two hundred three thousand, one hundred twenty-one".