51018521 has 4 divisors (see below), whose sum is σ = 51356544. Its totient is φ = 50680500.

The previous prime is 51018503. The next prime is 51018533. The reversal of 51018521 is 12581015.

51018521 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51018521 - 2¹⁰ = 51017497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51018551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168785 + ... + 169086.

It is an arithmetic number, because the mean of its divisors is an integer number (12839136).

Almost surely, 2^51018521 is an apocalyptic number.

It is an amenable number.

51018521 is a deficient number, since it is larger than the sum of its proper divisors (338023).

51018521 is a wasteful number, since it uses less digits than its factorization.

51018521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338022.

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 51018521 is about 7142.7250402070. The cubic root of 51018521 is about 370.8878628842.

Adding to 51018521 its reverse (12581015), we get a palindrome (63599536).

The spelling of 51018521 in words is "fifty-one million, eighteen thousand, five hundred twenty-one".