121211211997 has 2 divisors, whose sum is σ = 121211211998. Its totient is φ = 121211211996.

The previous prime is 121211211973. The next prime is 121211212051. The reversal of 121211211997 is 799112112121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119692473156 + 1518738841 = 345966^2 + 38971^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121211211997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121211211917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60605605998 + 60605605999.

It is an arithmetic number, because the mean of its divisors is an integer number (60605605999).

Almost surely, 2^121211211997 is an apocalyptic number.

It is an amenable number.

121211211997 is a deficient number, since it is larger than the sum of its proper divisors (1).

121211211997 is an equidigital number, since it uses as much as digits as its factorization.

121211211997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 37.

The spelling of 121211211997 in words is "one hundred twenty-one billion, two hundred eleven million, two hundred eleven thousand, nine hundred ninety-seven".