1242421 has 2 divisors, whose sum is σ = 1242422. Its totient is φ = 1242420.

The previous prime is 1242419. The next prime is 1242457.

1242421 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1234321 + 8100 = 1111^2 + 90^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 1242421 - 2¹ = 1242419 is a prime.

Together with 1242419, it forms a pair of twin primes.

It is an Ulam number.

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 1242395 and 1242404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1242121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621210 + 621211.

It is an arithmetic number, because the mean of its divisors is an integer number (621211).

2^1242421 is an apocalyptic number.

It is an amenable number.

1242421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242421 is an equidigital number, since it uses as much as digits as its factorization.

1242421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 128, while the sum is 16.

The square root of 1242421 is about 1114.6394035741. The cubic root of 1242421 is about 107.5035801944.

The spelling of 1242421 in words is "one million, two hundred forty-two thousand, four hundred twenty-one".