212661623660537 has 2 divisors, whose sum is σ = 212661623660538. Its totient is φ = 212661623660536.

The previous prime is 212661623660527. The next prime is 212661623660579. The reversal of 212661623660537 is 735066326166212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 181716223406656 + 30945400253881 = 13480216^2 + 5562859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212661623660537 is a prime.

It is a super-2 number, since 2×212661623660537² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (212661623660527) 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, 106330811830268 + 106330811830269.

It is an arithmetic number, because the mean of its divisors is an integer number (106330811830269).

Almost surely, 2^{212661623660537} is an apocalyptic number.

It is an amenable number.

212661623660537 is a deficient number, since it is larger than the sum of its proper divisors (1).

212661623660537 is an equidigital number, since it uses as much as digits as its factorization.

212661623660537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19595520, while the sum is 56.

The spelling of 212661623660537 in words is "two hundred twelve trillion, six hundred sixty-one billion, six hundred twenty-three million, six hundred sixty thousand, five hundred thirty-seven".