1320591421 has 2 divisors, whose sum is σ = 1320591422. Its totient is φ = 1320591420.

The previous prime is 1320591403. The next prime is 1320591449. The reversal of 1320591421 is 1241950231.

It is an a-pointer prime, because the next prime (1320591449) can be obtained adding 1320591421 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1216265625 + 104325796 = 34875^2 + 10214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320591421 - 2²¹ = 1318494269 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1320591421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1320591451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660295710 + 660295711.

It is an arithmetic number, because the mean of its divisors is an integer number (660295711).

Almost surely, 2^1320591421 is an apocalyptic number.

It is an amenable number.

1320591421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320591421 is an equidigital number, since it uses as much as digits as its factorization.

1320591421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 1320591421 is about 36339.9425013304. The cubic root of 1320591421 is about 1097.1251158115.

The spelling of 1320591421 in words is "one billion, three hundred twenty million, five hundred ninety-one thousand, four hundred twenty-one".