121213210123 has 2 divisors, whose sum is σ = 121213210124. Its totient is φ = 121213210122.

The previous prime is 121213210121. The next prime is 121213210147. The reversal of 121213210123 is 321012312121.

It is a weak prime.

It is an emirp because it is prime and its reverse (321012312121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121213210123 - 2¹ = 121213210121 is a prime.

Together with 121213210121, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 121213210123.

It is not a weakly prime, because it can be changed into another prime (121213210121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60606605061 + 60606605062.

It is an arithmetic number, because the mean of its divisors is an integer number (60606605062).

Almost surely, 2^121213210123 is an apocalyptic number.

121213210123 is a deficient number, since it is larger than the sum of its proper divisors (1).

121213210123 is an equidigital number, since it uses as much as digits as its factorization.

121213210123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 121213210123 its reverse (321012312121), we get a palindrome (442225522244).

The spelling of 121213210123 in words is "one hundred twenty-one billion, two hundred thirteen million, two hundred ten thousand, one hundred twenty-three".