51221761123487 has 2 divisors, whose sum is σ = 51221761123488. Its totient is φ = 51221761123486.

The previous prime is 51221761123457. The next prime is 51221761123523. The reversal of 51221761123487 is 78432116712215.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51221761123487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51221761123417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25610880561743 + 25610880561744.

It is an arithmetic number, because the mean of its divisors is an integer number (25610880561744).

Almost surely, 2^{51221761123487} is an apocalyptic number.

51221761123487 is a deficient number, since it is larger than the sum of its proper divisors (1).

51221761123487 is an equidigital number, since it uses as much as digits as its factorization.

51221761123487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1128960, while the sum is 50.

The spelling of 51221761123487 in words is "fifty-one trillion, two hundred twenty-one billion, seven hundred sixty-one million, one hundred twenty-three thousand, four hundred eighty-seven".