51390365481 has 36 divisors (see below), whose sum is σ = 92992100292. Its totient is φ = 27107002944.

The previous prime is 51390365479. The next prime is 51390365531. The reversal of 51390365481 is 18456309315.

51390365481 is a `hidden beast` number, since 5 + 13 + 90 + 3 + 6 + 548 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 29184597225 + 22205768256 = 170835^2 + 149016^2 .

It is not a de Polignac number, because 51390365481 - 2¹ = 51390365479 is a prime.

It is a super-2 number, since 2×51390365481² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51390365581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4476246 + ... + 4487711.

It is an arithmetic number, because the mean of its divisors is an integer number (2583113897).

Almost surely, 2^51390365481 is an apocalyptic number.

It is an amenable number.

51390365481 is a deficient number, since it is larger than the sum of its proper divisors (41601734811).

51390365481 is a wasteful number, since it uses less digits than its factorization.

51390365481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8963990 (or 8963980 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 51390365481 in words is "fifty-one billion, three hundred ninety million, three hundred sixty-five thousand, four hundred eighty-one".