51321780481 has 2 divisors, whose sum is σ = 51321780482. Its totient is φ = 51321780480.

The previous prime is 51321780431. The next prime is 51321780511. The reversal of 51321780481 is 18408712315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51213953025 + 107827456 = 226305^2 + 10384^2 .

It is a cyclic number.

It is not a de Polignac number, because 51321780481 - 2⁷ = 51321780353 is a prime.

It is a super-2 number, since 2×51321780481² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51321780421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25660890240 + 25660890241.

It is an arithmetic number, because the mean of its divisors is an integer number (25660890241).

Almost surely, 2^51321780481 is an apocalyptic number.

It is an amenable number.

51321780481 is a deficient number, since it is larger than the sum of its proper divisors (1).

51321780481 is an equidigital number, since it uses as much as digits as its factorization.

51321780481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 53760, while the sum is 40.

The spelling of 51321780481 in words is "fifty-one billion, three hundred twenty-one million, seven hundred eighty thousand, four hundred eighty-one".