1212121291 has 2 divisors, whose sum is σ = 1212121292. Its totient is φ = 1212121290.

The previous prime is 1212121279. The next prime is 1212121307. The reversal of 1212121291 is 1921212121.

It is a weak prime.

It is an emirp because it is prime and its reverse (1921212121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1212121291 - 2²⁵ = 1178566859 is a prime.

It is not a weakly prime, because it can be changed into another prime (1212121231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606060645 + 606060646.

It is an arithmetic number, because the mean of its divisors is an integer number (606060646).

Almost surely, 2^1212121291 is an apocalyptic number.

1212121291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212121291 is an equidigital number, since it uses as much as digits as its factorization.

1212121291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 22.

The square root of 1212121291 is about 34815.5323239499. The cubic root of 1212121291 is about 1066.2245873896.

The spelling of 1212121291 in words is "one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred ninety-one".