51551310431421 has 12 divisors (see below), whose sum is σ = 75483045107548. Its totient is φ = 33896752064064.

The previous prime is 51551310431419. The next prime is 51551310431431. The reversal of 51551310431421 is 12413401315515.

51551310431421 is a `hidden beast` number, since 5 + 1 + 5 + 5 + 1 + 310 + 4 + 314 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 30168500967396 + 21382809464025 = 5492586^2 + 4624155^2 .

It is not a de Polignac number, because 51551310431421 - 2¹ = 51551310431419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51551310431431) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39232351270 + ... + 39232352583.

Almost surely, 2^{51551310431421} is an apocalyptic number.

It is an amenable number.

51551310431421 is a deficient number, since it is larger than the sum of its proper divisors (23931734676127).

51551310431421 is a wasteful number, since it uses less digits than its factorization.

51551310431421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78464703932 (or 78464703929 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

Adding to 51551310431421 its reverse (12413401315515), we get a palindrome (63964711746936).

The spelling of 51551310431421 in words is "fifty-one trillion, five hundred fifty-one billion, three hundred ten million, four hundred thirty-one thousand, four hundred twenty-one".