1191561 has 16 divisors (see below), whose sum is σ = 1895424. Its totient is φ = 651024.

The previous prime is 1191559. The next prime is 1191563. The reversal of 1191561 is 1651911.

1191561 is nontrivially palindromic in base 2.

It is an interprime number because it is at equal distance from previous prime (1191559) and next prime (1191563).

It is not a de Polignac number, because 1191561 - 2¹ = 1191559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 751 + ... + 1716.

It is an arithmetic number, because the mean of its divisors is an integer number (118464).

2^1191561 is an apocalyptic number.

It is an amenable number.

1191561 is a deficient number, since it is larger than the sum of its proper divisors (703863).

1191561 is a wasteful number, since it uses less digits than its factorization.

1191561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2500.

The product of its digits is 270, while the sum is 24.

The square root of 1191561 is about 1091.5864601579. The cubic root of 1191561 is about 106.0161658031.

The spelling of 1191561 in words is "one million, one hundred ninety-one thousand, five hundred sixty-one".