61534536221 has 2 divisors, whose sum is σ = 61534536222. Its totient is φ = 61534536220.

The previous prime is 61534536169. The next prime is 61534536233. The reversal of 61534536221 is 12263543516.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43796025625 + 17738510596 = 209275^2 + 133186^2 .

It is a cyclic number.

It is not a de Polignac number, because 61534536221 - 2⁶ = 61534536157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61534536241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30767268110 + 30767268111.

It is an arithmetic number, because the mean of its divisors is an integer number (30767268111).

Almost surely, 2^61534536221 is an apocalyptic number.

It is an amenable number.

61534536221 is a deficient number, since it is larger than the sum of its proper divisors (1).

61534536221 is an equidigital number, since it uses as much as digits as its factorization.

61534536221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 38.

The spelling of 61534536221 in words is "sixty-one billion, five hundred thirty-four million, five hundred thirty-six thousand, two hundred twenty-one".