209212717057 has 2 divisors, whose sum is σ = 209212717058. Its totient is φ = 209212717056.

The previous prime is 209212717019. The next prime is 209212717151. The reversal of 209212717057 is 750717212902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209108656656 + 104060401 = 457284^2 + 10201^2 .

It is a cyclic number.

It is not a de Polignac number, because 209212717057 - 2²³ = 209204328449 is a prime.

It is not a weakly prime, because it can be changed into another prime (209212717957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104606358528 + 104606358529.

It is an arithmetic number, because the mean of its divisors is an integer number (104606358529).

Almost surely, 2^209212717057 is an apocalyptic number.

It is an amenable number.

209212717057 is a deficient number, since it is larger than the sum of its proper divisors (1).

209212717057 is an equidigital number, since it uses as much as digits as its factorization.

209212717057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 123480, while the sum is 43.

Adding to 209212717057 its reverse (750717212902), we get a palindrome (959929929959).

The spelling of 209212717057 in words is "two hundred nine billion, two hundred twelve million, seven hundred seventeen thousand, fifty-seven".