1331802721 has 2 divisors, whose sum is σ = 1331802722. Its totient is φ = 1331802720.

The previous prime is 1331802707. The next prime is 1331802727. The reversal of 1331802721 is 1272081331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1004192721 + 327610000 = 31689^2 + 18100^2 .

It is a cyclic number.

It is not a de Polignac number, because 1331802721 - 2⁹ = 1331802209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1331802721.

It is not a weakly prime, because it can be changed into another prime (1331802727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665901360 + 665901361.

It is an arithmetic number, because the mean of its divisors is an integer number (665901361).

Almost surely, 2^1331802721 is an apocalyptic number.

It is an amenable number.

1331802721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331802721 is an equidigital number, since it uses as much as digits as its factorization.

1331802721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 1331802721 is about 36493.8723760579. The cubic root of 1331802721 is about 1100.2210908213.

The spelling of 1331802721 in words is "one billion, three hundred thirty-one million, eight hundred two thousand, seven hundred twenty-one".