1197821 has 2 divisors, whose sum is σ = 1197822. Its totient is φ = 1197820.

The previous prime is 1197799. The next prime is 1197827. The reversal of 1197821 is 1287911.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 972196 + 225625 = 986^2 + 475^2 .

It is a cyclic number.

It is not a de Polignac number, because 1197821 - 2¹⁴ = 1181437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1197827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 598910 + 598911.

It is an arithmetic number, because the mean of its divisors is an integer number (598911).

2^1197821 is an apocalyptic number.

It is an amenable number.

1197821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1197821 is an equidigital number, since it uses as much as digits as its factorization.

1197821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 29.

The square root of 1197821 is about 1094.4500902280. The cubic root of 1197821 is about 106.2014975855.

The spelling of 1197821 in words is "one million, one hundred ninety-seven thousand, eight hundred twenty-one".