1228191 has 4 divisors (see below), whose sum is σ = 1637592. Its totient is φ = 818792.

The previous prime is 1228187. The next prime is 1228193. The reversal of 1228191 is 1918221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1228191 - 2² = 1228187 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1228193) 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, 204696 + ... + 204701.

It is an arithmetic number, because the mean of its divisors is an integer number (409398).

2^1228191 is an apocalyptic number.

1228191 is a deficient number, since it is larger than the sum of its proper divisors (409401).

1228191 is an equidigital number, since it uses as much as digits as its factorization.

1228191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409400.

The product of its digits is 288, while the sum is 24.

The square root of 1228191 is about 1108.2377903681. The cubic root of 1228191 is about 107.0915744422.

It can be divided in two parts, 12 and 28191, that added together give a triangular number (28203 = T₂₃₇).

The spelling of 1228191 in words is "one million, two hundred twenty-eight thousand, one hundred ninety-one".