1219891 has 2 divisors, whose sum is σ = 1219892. Its totient is φ = 1219890.

The previous prime is 1219879. The next prime is 1219909. The reversal of 1219891 is 1989121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1219891 - 2⁵ = 1219859 is a prime.

It is a Chen prime.

1219891 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1219811) 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, 609945 + 609946.

It is an arithmetic number, because the mean of its divisors is an integer number (609946).

2^1219891 is an apocalyptic number.

1219891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1219891 is an equidigital number, since it uses as much as digits as its factorization.

1219891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 31.

The square root of 1219891 is about 1104.4867586350. The cubic root of 1219891 is about 106.8497906868.

The spelling of 1219891 in words is "one million, two hundred nineteen thousand, eight hundred ninety-one".