51356356421 has 16 divisors (see below), whose sum is σ = 54650505600. Its totient is φ = 48194497728.

The previous prime is 51356356399. The next prime is 51356356439. The reversal of 51356356421 is 12465365315.

It is a cyclic number.

It is not a de Polignac number, because 51356356421 - 2¹⁰ = 51356355397 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 (51356350421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106241 + ... + 337638.

It is an arithmetic number, because the mean of its divisors is an integer number (3415656600).

Almost surely, 2^51356356421 is an apocalyptic number.

It is an amenable number.

51356356421 is a deficient number, since it is larger than the sum of its proper divisors (3294149179).

51356356421 is a wasteful number, since it uses less digits than its factorization.

51356356421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444028.

The product of its digits is 324000, while the sum is 41.

The spelling of 51356356421 in words is "fifty-one billion, three hundred fifty-six million, three hundred fifty-six thousand, four hundred twenty-one".