1125991 has 2 divisors, whose sum is σ = 1125992. Its totient is φ = 1125990.

The previous prime is 1125973. The next prime is 1126031. The reversal of 1125991 is 1995211.

It is a weak prime.

It is an emirp because it is prime and its reverse (1995211) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1125991 - 2⁹ = 1125479 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1125911) 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 as a sum of consecutive naturals, namely, 562995 + 562996.

It is an arithmetic number, because the mean of its divisors is an integer number (562996).

2^1125991 is an apocalyptic number.

1125991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1125991 is an equidigital number, since it uses as much as digits as its factorization.

1125991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 810, while the sum is 28.

The square root of 1125991 is about 1061.1272308258. The cubic root of 1125991 is about 104.0347209020.

It can be divided in two parts, 1125 and 991, that added together give a square (2116 = 46²).

The spelling of 1125991 in words is "one million, one hundred twenty-five thousand, nine hundred ninety-one".