1220091 has 4 divisors (see below), whose sum is σ = 1626792. Its totient is φ = 813392.

The previous prime is 1220077. The next prime is 1220099. The reversal of 1220091 is 1900221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1900221 = 3 ⋅633407.

It is a cyclic number.

It is not a de Polignac number, because 1220091 - 2⁶ = 1220027 is a prime.

It is a D-number.

1220091 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1220091.

It is not an unprimeable number, because it can be changed into a prime (1220099) 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, 203346 + ... + 203351.

It is an arithmetic number, because the mean of its divisors is an integer number (406698).

2^1220091 is an apocalyptic number.

1220091 is a deficient number, since it is larger than the sum of its proper divisors (406701).

1220091 is an equidigital number, since it uses as much as digits as its factorization.

1220091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406700.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1220091 is about 1104.5772947150. The cubic root of 1220091 is about 106.8556296758.

The spelling of 1220091 in words is "one million, two hundred twenty thousand, ninety-one".