1211357857 has 2 divisors, whose sum is σ = 1211357858. Its totient is φ = 1211357856.

The previous prime is 1211357827. The next prime is 1211357867. The reversal of 1211357857 is 7587531121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1136431521 + 74926336 = 33711^2 + 8656^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211357857 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211357827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605678928 + 605678929.

It is an arithmetic number, because the mean of its divisors is an integer number (605678929).

Almost surely, 2^1211357857 is an apocalyptic number.

It is an amenable number.

1211357857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211357857 is an equidigital number, since it uses as much as digits as its factorization.

1211357857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58800, while the sum is 40.

The square root of 1211357857 is about 34804.5666112940. The cubic root of 1211357857 is about 1066.0006925642. Note that the first 3 decimals are identical.

Adding to 1211357857 its reverse (7587531121), we get a palindrome (8798888978).

The spelling of 1211357857 in words is "one billion, two hundred eleven million, three hundred fifty-seven thousand, eight hundred fifty-seven".