1236991 has 4 divisors (see below), whose sum is σ = 1413712. Its totient is φ = 1060272.

The previous prime is 1236979. The next prime is 1237001. The reversal of 1236991 is 1996321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1236991 - 2⁵ = 1236959 is a prime.

It is a super-3 number, since 3×1236991³ = 5678333216212770813, which contains 333 as substring.

It is a Duffinian number.

It is a plaindrome in base 8 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1236901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88350 + ... + 88363.

It is an arithmetic number, because the mean of its divisors is an integer number (353428).

2^1236991 is an apocalyptic number.

1236991 is a deficient number, since it is larger than the sum of its proper divisors (176721).

1236991 is an equidigital number, since it uses as much as digits as its factorization.

1236991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176720.

The product of its digits is 2916, while the sum is 31.

The square root of 1236991 is about 1112.2009710479. The cubic root of 1236991 is about 107.3467367065.

The spelling of 1236991 in words is "one million, two hundred thirty-six thousand, nine hundred ninety-one".