1220189 has 4 divisors (see below), whose sum is σ = 1222620. Its totient is φ = 1217760.

The previous prime is 1220171. The next prime is 1220203. The reversal of 1220189 is 9810221.

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

It can be written as a sum of positive squares in 2 ways, for example, as 511225 + 708964 = 715^2 + 842^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220189 - 2¹⁶ = 1154653 is a prime.

It is a super-2 number, since 2×1220189² = 2977722391442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220489) 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, 152 + ... + 1569.

It is an arithmetic number, because the mean of its divisors is an integer number (305655).

2^1220189 is an apocalyptic number.

It is an amenable number.

1220189 is a deficient number, since it is larger than the sum of its proper divisors (2431).

1220189 is an equidigital number, since it uses as much as digits as its factorization.

1220189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2430.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1220189 is about 1104.6216546854. The cubic root of 1220189 is about 106.8584905474.

The spelling of 1220189 in words is "one million, two hundred twenty thousand, one hundred eighty-nine".