1212121997 has 2 divisors, whose sum is σ = 1212121998. Its totient is φ = 1212121996.

The previous prime is 1212121849. The next prime is 1212122039. The reversal of 1212121997 is 7991212121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1032401161 + 179720836 = 32131^2 + 13406^2 .

It is an emirp because it is prime and its reverse (7991212121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1212121997 - 2⁸ = 1212121741 is a prime.

It is a super-2 number, since 2×1212121997² = 2938479471222536018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212127997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606060998 + 606060999.

It is an arithmetic number, because the mean of its divisors is an integer number (606060999).

Almost surely, 2^1212121997 is an apocalyptic number.

It is an amenable number.

1212121997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212121997 is an equidigital number, since it uses as much as digits as its factorization.

1212121997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 35.

The square root of 1212121997 is about 34815.5424631012. The cubic root of 1212121997 is about 1066.2247943971.

The spelling of 1212121997 in words is "one billion, two hundred twelve million, one hundred twenty-one thousand, nine hundred ninety-seven".