51504521 has 4 divisors (see below), whose sum is σ = 53743872. Its totient is φ = 49265172.

The previous prime is 51504511. The next prime is 51504529. The reversal of 51504521 is 12540515.

It is a happy number.

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 not a de Polignac number, because 51504521 - 2⁶ = 51504457 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 2239327 = 51504521 / (5 + 1 + 5 + 0 + 4 + 5 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51504529) 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, 1119641 + ... + 1119686.

It is an arithmetic number, because the mean of its divisors is an integer number (13435968).

Almost surely, 2^51504521 is an apocalyptic number.

It is an amenable number.

51504521 is a deficient number, since it is larger than the sum of its proper divisors (2239351).

51504521 is a wasteful number, since it uses less digits than its factorization.

51504521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2239350.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 51504521 is about 7176.6650332867. The cubic root of 51504521 is about 372.0618297235.

It can be divided in two parts, 51504 and 521, that added together give a palindrome (52025).

The spelling of 51504521 in words is "fifty-one million, five hundred four thousand, five hundred twenty-one".