1211256997 has 2 divisors, whose sum is σ = 1211256998. Its totient is φ = 1211256996.

The previous prime is 1211256989. The next prime is 1211257001. The reversal of 1211256997 is 7996521121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1081160161 + 130096836 = 32881^2 + 11406^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211256997 - 2³ = 1211256989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211256197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605628498 + 605628499.

It is an arithmetic number, because the mean of its divisors is an integer number (605628499).

Almost surely, 2^1211256997 is an apocalyptic number.

It is an amenable number.

1211256997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211256997 is an equidigital number, since it uses as much as digits as its factorization.

1211256997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 43.

The square root of 1211256997 is about 34803.1176333385. The cubic root of 1211256997 is about 1065.9711059827.

The spelling of 1211256997 in words is "one billion, two hundred eleven million, two hundred fifty-six thousand, nine hundred ninety-seven".