1209919 has 4 divisors (see below), whose sum is σ = 1212120. Its totient is φ = 1207720.

The previous prime is 1209889. The next prime is 1209931. The reversal of 1209919 is 9199021.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1209919 - 2¹⁹ = 685631 is a prime.

It is a super-2 number, since 2×1209919² = 2927807973122, which contains 22 as substring.

It is a Duffinian number.

1209919 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209959) 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, 537 + ... + 1645.

It is an arithmetic number, because the mean of its divisors is an integer number (303030).

2^1209919 is an apocalyptic number.

1209919 is a deficient number, since it is larger than the sum of its proper divisors (2201).

1209919 is a wasteful number, since it uses less digits than its factorization.

1209919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2200.

The product of its (nonzero) digits is 1458, while the sum is 31.

The square root of 1209919 is about 1099.9631812020. The cubic root of 1209919 is about 106.5578458335.

The spelling of 1209919 in words is "one million, two hundred nine thousand, nine hundred nineteen".