1145561 has 4 divisors (see below), whose sum is σ = 1195392. Its totient is φ = 1095732.

The previous prime is 1145539. The next prime is 1145593. The reversal of 1145561 is 1655411.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1655411 = 617 ⋅2683.

It is a cyclic number.

It is not a de Polignac number, because 1145561 - 2⁶ = 1145497 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 49807 = 1145561 / (1 + 1 + 4 + 5 + 5 + 6 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1145461) 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, 24881 + ... + 24926.

It is an arithmetic number, because the mean of its divisors is an integer number (298848).

2^1145561 is an apocalyptic number.

It is an amenable number.

1145561 is a deficient number, since it is larger than the sum of its proper divisors (49831).

1145561 is an equidigital number, since it uses as much as digits as its factorization.

1145561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49830.

The product of its digits is 600, while the sum is 23.

The square root of 1145561 is about 1070.3088339353. The cubic root of 1145561 is about 104.6339787756.

The spelling of 1145561 in words is "one million, one hundred forty-five thousand, five hundred sixty-one".