51543425421 has 12 divisors (see below), whose sum is σ = 74456503420. Its totient is φ = 34360027200.

The previous prime is 51543425399. The next prime is 51543425429. The reversal of 51543425421 is 12452434515.

51543425421 is a `hidden beast` number, since 5 + 1 + 543 + 42 + 54 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 51349826025 + 193599396 = 226605^2 + 13914^2 .

It is not a de Polignac number, because 51543425421 - 2⁶ = 51543425357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51543425429) 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, 36976 + ... + 323193.

Almost surely, 2^51543425421 is an apocalyptic number.

It is an amenable number.

51543425421 is a deficient number, since it is larger than the sum of its proper divisors (22913077999).

51543425421 is a wasteful number, since it uses less digits than its factorization.

51543425421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376076 (or 376073 counting only the distinct ones).

The product of its digits is 96000, while the sum is 36.

Adding to 51543425421 its reverse (12452434515), we get a palindrome (63995859936).

The spelling of 51543425421 in words is "fifty-one billion, five hundred forty-three million, four hundred twenty-five thousand, four hundred twenty-one".