1309421 has 2 divisors, whose sum is σ = 1309422. Its totient is φ = 1309420.

The previous prime is 1309411. The next prime is 1309463. The reversal of 1309421 is 1249031.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1297321 + 12100 = 1139^2 + 110^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1309421 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1309393 and 1309402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1309411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 654710 + 654711.

It is an arithmetic number, because the mean of its divisors is an integer number (654711).

2^1309421 is an apocalyptic number.

It is an amenable number.

1309421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1309421 is an equidigital number, since it uses as much as digits as its factorization.

1309421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 1309421 is about 1144.2993489468. The cubic root of 1309421 is about 109.4022953373.

The spelling of 1309421 in words is "one million, three hundred nine thousand, four hundred twenty-one".