1187591 has 4 divisors (see below), whose sum is σ = 1192800. Its totient is φ = 1182384.

The previous prime is 1187587. The next prime is 1187623. The reversal of 1187591 is 1957811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1957811 = 727 ⋅2693.

It is a cyclic number.

It is not a de Polignac number, because 1187591 - 2² = 1187587 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 (1187551) 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, 2246 + ... + 2723.

It is an arithmetic number, because the mean of its divisors is an integer number (298200).

2^1187591 is an apocalyptic number.

1187591 is a deficient number, since it is larger than the sum of its proper divisors (5209).

1187591 is an equidigital number, since it uses as much as digits as its factorization.

1187591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5208.

The product of its digits is 2520, while the sum is 32.

The square root of 1187591 is about 1089.7664887489. The cubic root of 1187591 is about 105.8982945194.

The spelling of 1187591 in words is "one million, one hundred eighty-seven thousand, five hundred ninety-one".