1698421 has 4 divisors (see below), whose sum is σ = 1720000. Its totient is φ = 1676844.

The previous prime is 1698413. The next prime is 1698427. The reversal of 1698421 is 1248961.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1698421 - 2³ = 1698413 is a prime.

It is a Duffinian number.

1698421 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1698427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10671 + ... + 10828.

It is an arithmetic number, because the mean of its divisors is an integer number (430000).

2^1698421 is an apocalyptic number.

It is an amenable number.

1698421 is a deficient number, since it is larger than the sum of its proper divisors (21579).

1698421 is an equidigital number, since it uses as much as digits as its factorization.

1698421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21578.

The product of its digits is 3456, while the sum is 31.

The square root of 1698421 is about 1303.2348215115. The cubic root of 1698421 is about 119.3113565708.

The spelling of 1698421 in words is "one million, six hundred ninety-eight thousand, four hundred twenty-one".