1242213251 has 2 divisors, whose sum is σ = 1242213252. Its totient is φ = 1242213250.

The previous prime is 1242213227. The next prime is 1242213253. The reversal of 1242213251 is 1523122421.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1242213251 - 2¹⁸ = 1241951107 is a prime.

Together with 1242213253, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1242213253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621106625 + 621106626.

It is an arithmetic number, because the mean of its divisors is an integer number (621106626).

Almost surely, 2^1242213251 is an apocalyptic number.

1242213251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242213251 is an equidigital number, since it uses as much as digits as its factorization.

1242213251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 23.

The square root of 1242213251 is about 35245.0457653271. The cubic root of 1242213251 is about 1074.9758786006.

Adding to 1242213251 its reverse (1523122421), we get a palindrome (2765335672).

The spelling of 1242213251 in words is "one billion, two hundred forty-two million, two hundred thirteen thousand, two hundred fifty-one".