21201210212057 has 2 divisors, whose sum is σ = 21201210212058. Its totient is φ = 21201210212056.

The previous prime is 21201210211999. The next prime is 21201210212111. The reversal of 21201210212057 is 75021201210212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10681235822656 + 10519974389401 = 3268216^2 + 3243451^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201210212057 is a prime.

It is not a weakly prime, because it can be changed into another prime (21201210212657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600605106028 + 10600605106029.

It is an arithmetic number, because the mean of its divisors is an integer number (10600605106029).

Almost surely, 2^{21201210212057} is an apocalyptic number.

It is an amenable number.

21201210212057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201210212057 is an equidigital number, since it uses as much as digits as its factorization.

21201210212057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 26.

Adding to 21201210212057 its reverse (75021201210212), we get a palindrome (96222411422269).

The spelling of 21201210212057 in words is "twenty-one trillion, two hundred one billion, two hundred ten million, two hundred twelve thousand, fifty-seven".