1291421 has 2 divisors, whose sum is σ = 1291422. Its totient is φ = 1291420.

The previous prime is 1291391. The next prime is 1291447. The reversal of 1291421 is 1241921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 972196 + 319225 = 986^2 + 565^2 .

It is an emirp because it is prime and its reverse (1241921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1291421 - 2⁶ = 1291357 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1291393 and 1291402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645710 + 645711.

It is an arithmetic number, because the mean of its divisors is an integer number (645711).

2^1291421 is an apocalyptic number.

It is an amenable number.

1291421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291421 is an equidigital number, since it uses as much as digits as its factorization.

1291421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 20.

The square root of 1291421 is about 1136.4070573522. The cubic root of 1291421 is about 108.8986798005.

The spelling of 1291421 in words is "one million, two hundred ninety-one thousand, four hundred twenty-one".