212685437561 has 2 divisors, whose sum is σ = 212685437562. Its totient is φ = 212685437560.

The previous prime is 212685437527. The next prime is 212685437567. The reversal of 212685437561 is 165734586212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128733852025 + 83951585536 = 358795^2 + 289744^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212685437561 is a prime.

It is not a weakly prime, because it can be changed into another prime (212685437567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106342718780 + 106342718781.

It is an arithmetic number, because the mean of its divisors is an integer number (106342718781).

Almost surely, 2^212685437561 is an apocalyptic number.

It is an amenable number.

212685437561 is a deficient number, since it is larger than the sum of its proper divisors (1).

212685437561 is an equidigital number, since it uses as much as digits as its factorization.

212685437561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2419200, while the sum is 50.

The spelling of 212685437561 in words is "two hundred twelve billion, six hundred eighty-five million, four hundred thirty-seven thousand, five hundred sixty-one".