1121561 has 12 divisors (see below), whose sum is σ = 1335168. Its totient is φ = 938952.

The previous prime is 1121557. The next prime is 1121599. The reversal of 1121561 is 1651211.

It is not a de Polignac number, because 1121561 - 2² = 1121557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1121261) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2060 + ... + 2546.

It is an arithmetic number, because the mean of its divisors is an integer number (111264).

2^1121561 is an apocalyptic number.

It is an amenable number.

1121561 is a deficient number, since it is larger than the sum of its proper divisors (213607).

1121561 is an equidigital number, since it uses as much as digits as its factorization.

1121561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548 (or 541 counting only the distinct ones).

The product of its digits is 60, while the sum is 17.

The square root of 1121561 is about 1059.0377708090. The cubic root of 1121561 is about 103.8981065640.

Adding to 1121561 its reverse (1651211), we get a palindrome (2772772).

It can be divided in two parts, 1121 and 561, that multiplied together give a triangular number (628881 = T₁₁₂₁).

The spelling of 1121561 in words is "one million, one hundred twenty-one thousand, five hundred sixty-one".