1961209 has 4 divisors (see below), whose sum is σ = 1964416. Its totient is φ = 1958004.

The previous prime is 1961173. The next prime is 1961213. The reversal of 1961209 is 9021691.

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 1961209 - 2¹¹ = 1959161 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1961249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 369 + ... + 2014.

It is an arithmetic number, because the mean of its divisors is an integer number (491104).

2^1961209 is an apocalyptic number.

It is an amenable number.

1961209 is a deficient number, since it is larger than the sum of its proper divisors (3207).

1961209 is an equidigital number, since it uses as much as digits as its factorization.

1961209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3206.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 1961209 is about 1400.4317191495. The cubic root of 1961209 is about 125.1722212763.

The spelling of 1961209 in words is "one million, nine hundred sixty-one thousand, two hundred nine".