51554116126421 has 2 divisors, whose sum is σ = 51554116126422. Its totient is φ = 51554116126420.

The previous prime is 51554116126393. The next prime is 51554116126463. The reversal of 51554116126421 is 12462161145515.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48768071095396 + 2786045031025 = 6983414^2 + 1669145^2 .

It is a cyclic number.

It is not a de Polignac number, because 51554116126421 - 2¹⁰ = 51554116125397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51554116626421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25777058063210 + 25777058063211.

It is an arithmetic number, because the mean of its divisors is an integer number (25777058063211).

Almost surely, 2^{51554116126421} is an apocalyptic number.

It is an amenable number.

51554116126421 is a deficient number, since it is larger than the sum of its proper divisors (1).

51554116126421 is an equidigital number, since it uses as much as digits as its factorization.

51554116126421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288000, while the sum is 44.

The spelling of 51554116126421 in words is "fifty-one trillion, five hundred fifty-four billion, one hundred sixteen million, one hundred twenty-six thousand, four hundred twenty-one".