1398421 has 2 divisors, whose sum is σ = 1398422. Its totient is φ = 1398420.

The previous prime is 1398413. The next prime is 1398427. The reversal of 1398421 is 1248931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1134225 + 264196 = 1065^2 + 514^2 .

It is a cyclic number.

It is not a de Polignac number, because 1398421 - 2³ = 1398413 is a prime.

It is a zygodrome in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 1398421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1398427) 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, 699210 + 699211.

It is an arithmetic number, because the mean of its divisors is an integer number (699211).

2^1398421 is an apocalyptic number.

It is an amenable number.

1398421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1398421 is an equidigital number, since it uses as much as digits as its factorization.

1398421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 28.

The square root of 1398421 is about 1182.5485190892. The cubic root of 1398421 is about 111.8268210095.

The spelling of 1398421 in words is "one million, three hundred ninety-eight thousand, four hundred twenty-one".