1121591 has 4 divisors (see below), whose sum is σ = 1129800. Its totient is φ = 1113384.

The previous prime is 1121557. The next prime is 1121599. The reversal of 1121591 is 1951211.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1951211 = 43 ⋅45377.

It is a cyclic number.

It is not a de Polignac number, because 1121591 - 2¹⁴ = 1105207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121599) 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 in 3 ways as a sum of consecutive naturals, for example, 3896 + ... + 4173.

It is an arithmetic number, because the mean of its divisors is an integer number (282450).

2^1121591 is an apocalyptic number.

1121591 is a deficient number, since it is larger than the sum of its proper divisors (8209).

1121591 is an equidigital number, since it uses as much as digits as its factorization.

1121591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8208.

The product of its digits is 90, while the sum is 20.

The square root of 1121591 is about 1059.0519345150. The cubic root of 1121591 is about 103.8990329263.

The spelling of 1121591 in words is "one million, one hundred twenty-one thousand, five hundred ninety-one".