1209971 has 4 divisors (see below), whose sum is σ = 1382832. Its totient is φ = 1037112.

The previous prime is 1209959. The next prime is 1209973. The reversal of 1209971 is 1799021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1799021 = 7 ⋅257003.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1209971 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 (1209973) 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, 86420 + ... + 86433.

It is an arithmetic number, because the mean of its divisors is an integer number (345708).

2^1209971 is an apocalyptic number.

1209971 is a deficient number, since it is larger than the sum of its proper divisors (172861).

1209971 is an equidigital number, since it uses as much as digits as its factorization.

1209971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172860.

The product of its (nonzero) digits is 1134, while the sum is 29.

The square root of 1209971 is about 1099.9868181028. The cubic root of 1209971 is about 106.5593723623.

Adding to 1209971 its sum of digits (29), we get a square (1210000 = 1100²).

The spelling of 1209971 in words is "one million, two hundred nine thousand, nine hundred seventy-one".