1231421 has 2 divisors, whose sum is σ = 1231422. Its totient is φ = 1231420.

The previous prime is 1231411. The next prime is 1231423. The reversal of 1231421 is 1241321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 940900 + 290521 = 970^2 + 539^2 .

It is an emirp because it is prime and its reverse (1241321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1231421 - 2⁶ = 1231357 is a prime.

It is a Sophie Germain prime.

Together with 1231423, it forms a pair of twin primes.

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 = 1231396 and 1231405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615710 + 615711.

It is an arithmetic number, because the mean of its divisors is an integer number (615711).

2^1231421 is an apocalyptic number.

It is an amenable number.

1231421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231421 is an equidigital number, since it uses as much as digits as its factorization.

1231421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48, while the sum is 14.

The square root of 1231421 is about 1109.6941019939. The cubic root of 1231421 is about 107.1853717416.

Adding to 1231421 its reverse (1241321), we get a palindrome (2472742).

The spelling of 1231421 in words is "one million, two hundred thirty-one thousand, four hundred twenty-one".