1211999 has 2 divisors, whose sum is σ = 1212000. Its totient is φ = 1211998.

The previous prime is 1211983. The next prime is 1212011. The reversal of 1211999 is 9991121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211999 - 2⁴ = 1211983 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605999 + 606000.

It is an arithmetic number, because the mean of its divisors is an integer number (606000).

2^1211999 is an apocalyptic number.

1211999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211999 is an equidigital number, since it uses as much as digits as its factorization.

1211999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1458, while the sum is 32.

The square root of 1211999 is about 1100.9082613915. The cubic root of 1211999 is about 106.6188729026.

The spelling of 1211999 in words is "one million, two hundred eleven thousand, nine hundred ninety-nine".