51605502061 has 2 divisors, whose sum is σ = 51605502062. Its totient is φ = 51605502060.

The previous prime is 51605502043. The next prime is 51605502077. The reversal of 51605502061 is 16020550615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47564992836 + 4040509225 = 218094^2 + 63565^2 .

It is a cyclic number.

It is not a de Polignac number, because 51605502061 - 2⁷ = 51605501933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51605502041) 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, 25802751030 + 25802751031.

It is an arithmetic number, because the mean of its divisors is an integer number (25802751031).

Almost surely, 2^51605502061 is an apocalyptic number.

It is an amenable number.

51605502061 is a deficient number, since it is larger than the sum of its proper divisors (1).

51605502061 is an equidigital number, since it uses as much as digits as its factorization.

51605502061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9000, while the sum is 31.

The spelling of 51605502061 in words is "fifty-one billion, six hundred five million, five hundred two thousand, sixty-one".