51503521 has 4 divisors (see below), whose sum is σ = 51534100. Its totient is φ = 51472944.

The previous prime is 51503513. The next prime is 51503527. The reversal of 51503521 is 12530515.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47114496 + 4389025 = 6864^2 + 2095^2 .

It is a cyclic number.

It is not a de Polignac number, because 51503521 - 2³ = 51503513 is a prime.

It is a super-2 number, since 2×51503521² = 5305225350794882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51503492 and 51503501.

It is not an unprimeable number, because it can be changed into a prime (51503527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12606 + ... + 16183.

It is an arithmetic number, because the mean of its divisors is an integer number (12883525).

Almost surely, 2^51503521 is an apocalyptic number.

It is an amenable number.

51503521 is a deficient number, since it is larger than the sum of its proper divisors (30579).

51503521 is a wasteful number, since it uses less digits than its factorization.

51503521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30578.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 51503521 is about 7176.5953627051. The cubic root of 51503521 is about 372.0594217522.

The spelling of 51503521 in words is "fifty-one million, five hundred three thousand, five hundred twenty-one".