121212111931 has 2 divisors, whose sum is σ = 121212111932. Its totient is φ = 121212111930.

The previous prime is 121212111899. The next prime is 121212111947. The reversal of 121212111931 is 139111212121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121212111931 - 2⁵ = 121212111899 is a prime.

It is a super-2 number, since 2×121212111931² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121212111896 and 121212111905.

It is not a weakly prime, because it can be changed into another prime (121212111991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60606055965 + 60606055966.

It is an arithmetic number, because the mean of its divisors is an integer number (60606055966).

Almost surely, 2^121212111931 is an apocalyptic number.

121212111931 is a deficient number, since it is larger than the sum of its proper divisors (1).

121212111931 is an equidigital number, since it uses as much as digits as its factorization.

121212111931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 25.

The spelling of 121212111931 in words is "one hundred twenty-one billion, two hundred twelve million, one hundred eleven thousand, nine hundred thirty-one".