1421209 has 4 divisors (see below), whose sum is σ = 1438416. Its totient is φ = 1404004.

The previous prime is 1421191. The next prime is 1421213. The reversal of 1421209 is 9021241.

1421209 = T₁₄₂ + T₁₄₃ + ... + T₂₂₄.

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 1421209 - 2⁹ = 1420697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1421249) 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, 8479 + ... + 8644.

It is an arithmetic number, because the mean of its divisors is an integer number (359604).

2^1421209 is an apocalyptic number.

It is an amenable number.

1421209 is a deficient number, since it is larger than the sum of its proper divisors (17207).

1421209 is an equidigital number, since it uses as much as digits as its factorization.

1421209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17206.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 1421209 is about 1192.1447059816. The cubic root of 1421209 is about 112.4309765900.

It can be divided in two parts, 142120 and 9, that added together give a square (142129 = 377²).

The spelling of 1421209 in words is "one million, four hundred twenty-one thousand, two hundred nine".