51661561060013 has 2 divisors, whose sum is σ = 51661561060014. Its totient is φ = 51661561060012.

The previous prime is 51661561060003. The next prime is 51661561060027. The reversal of 51661561060013 is 31006016516615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26429695924324 + 25231865135689 = 5140982^2 + 5023133^2 .

It is a cyclic number.

It is not a de Polignac number, because 51661561060013 - 2²⁶ = 51661493951149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51661561060003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25830780530006 + 25830780530007.

It is an arithmetic number, because the mean of its divisors is an integer number (25830780530007).

Almost surely, 2^{51661561060013} is an apocalyptic number.

It is an amenable number.

51661561060013 is a deficient number, since it is larger than the sum of its proper divisors (1).

51661561060013 is an equidigital number, since it uses as much as digits as its factorization.

51661561060013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 41.

Adding to 51661561060013 its reverse (31006016516615), we get a palindrome (82667577576628).

The spelling of 51661561060013 in words is "fifty-one trillion, six hundred sixty-one billion, five hundred sixty-one million, sixty thousand, thirteen".