1197809 has 4 divisors (see below), whose sum is σ = 1236480. Its totient is φ = 1159140.

The previous prime is 1197799. The next prime is 1197821. The reversal of 1197809 is 9087911.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1197809 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1197829) 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, 19289 + ... + 19350.

It is an arithmetic number, because the mean of its divisors is an integer number (309120).

2^1197809 is an apocalyptic number.

It is an amenable number.

1197809 is a deficient number, since it is larger than the sum of its proper divisors (38671).

1197809 is an equidigital number, since it uses as much as digits as its factorization.

1197809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38670.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 1197809 is about 1094.4446080090. Note that the first 3 decimals coincide. The cubic root of 1197809 is about 106.2011429354.

The spelling of 1197809 in words is "one million, one hundred ninety-seven thousand, eight hundred nine".