1212206557 has 2 divisors, whose sum is σ = 1212206558. Its totient is φ = 1212206556.

The previous prime is 1212206509. The next prime is 1212206561. The reversal of 1212206557 is 7556022121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 895864761 + 316341796 = 29931^2 + 17786^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212206557 - 2²³ = 1203817949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212206357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606103278 + 606103279.

It is an arithmetic number, because the mean of its divisors is an integer number (606103279).

Almost surely, 2^1212206557 is an apocalyptic number.

It is an amenable number.

1212206557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212206557 is an equidigital number, since it uses as much as digits as its factorization.

1212206557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 1212206557 is about 34816.7568420725. The cubic root of 1212206557 is about 1066.2495877959.

Adding to 1212206557 its reverse (7556022121), we get a palindrome (8768228678).

The spelling of 1212206557 in words is "one billion, two hundred twelve million, two hundred six thousand, five hundred fifty-seven".