51231405421 has 8 divisors (see below), whose sum is σ = 61631766080. Its totient is φ = 41601441888.

The previous prime is 51231405391. The next prime is 51231405427. The reversal of 51231405421 is 12450413215.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51231405421 - 2⁷ = 51231405293 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51231405421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51231405427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 192599136 + ... + 192599401.

It is an arithmetic number, because the mean of its divisors is an integer number (7703970760).

Almost surely, 2^51231405421 is an apocalyptic number.

It is an amenable number.

51231405421 is a deficient number, since it is larger than the sum of its proper divisors (10400360659).

51231405421 is a wasteful number, since it uses less digits than its factorization.

51231405421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385198563.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 51231405421 its reverse (12450413215), we get a palindrome (63681818636).

The spelling of 51231405421 in words is "fifty-one billion, two hundred thirty-one million, four hundred five thousand, four hundred twenty-one".