51206404481 has 4 divisors (see below), whose sum is σ = 51207096132. Its totient is φ = 51205712832.

The previous prime is 51206404477. The next prime is 51206404493. The reversal of 51206404481 is 18440460215.

51206404481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18440460215 = 5 ⋅3688092043.

It can be written as a sum of positive squares in 2 ways, for example, as 30415360000 + 20791044481 = 174400^2 + 144191^2 .

It is a cyclic number.

It is not a de Polignac number, because 51206404481 - 2² = 51206404477 is a prime.

It is a super-2 number, since 2×51206404481² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51206404471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219356 + ... + 387981.

It is an arithmetic number, because the mean of its divisors is an integer number (12801774033).

Almost surely, 2^51206404481 is an apocalyptic number.

It is an amenable number.

51206404481 is a deficient number, since it is larger than the sum of its proper divisors (691651).

51206404481 is an equidigital number, since it uses as much as digits as its factorization.

51206404481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691650.

The product of its (nonzero) digits is 30720, while the sum is 35.

Adding to 51206404481 its reverse (18440460215), we get a palindrome (69646864696).

The spelling of 51206404481 in words is "fifty-one billion, two hundred six million, four hundred four thousand, four hundred eighty-one".