1331201021 has 2 divisors, whose sum is σ = 1331201022. Its totient is φ = 1331201020.

The previous prime is 1331200999. The next prime is 1331201023. The reversal of 1331201021 is 1201021331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1331155225 + 45796 = 36485^2 + 214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1331201021 - 2¹⁰ = 1331199997 is a prime.

It is a super-2 number, since 2×1331201021² = 3544192316622884882, which contains 22 as substring.

Together with 1331201023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1331200987 and 1331201005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331201023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665600510 + 665600511.

It is an arithmetic number, because the mean of its divisors is an integer number (665600511).

Almost surely, 2^1331201021 is an apocalyptic number.

It is an amenable number.

1331201021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331201021 is an equidigital number, since it uses as much as digits as its factorization.

1331201021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 1331201021 is about 36485.6275949859. The cubic root of 1331201021 is about 1100.0553748983.

Adding to 1331201021 its reverse (1201021331), we get a palindrome (2532222352).

The spelling of 1331201021 in words is "one billion, three hundred thirty-one million, two hundred one thousand, twenty-one".