121211999 has 2 divisors, whose sum is σ = 121212000. Its totient is φ = 121211998.

The previous prime is 121211977. The next prime is 121212017. The reversal of 121211999 is 999112121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121211999 - 2⁸ = 121211743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121211929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60605999 + 60606000.

It is an arithmetic number, because the mean of its divisors is an integer number (60606000).

Almost surely, 2^121211999 is an apocalyptic number.

121211999 is a deficient number, since it is larger than the sum of its proper divisors (1).

121211999 is an equidigital number, since it uses as much as digits as its factorization.

121211999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 35.

The square root of 121211999 is about 11009.6321010286. The cubic root of 121211999 is about 494.8974368331.

The spelling of 121211999 in words is "one hundred twenty-one million, two hundred eleven thousand, nine hundred ninety-nine".