51530531 has 4 divisors (see below), whose sum is σ = 55494432. Its totient is φ = 47566632.

The previous prime is 51530473. The next prime is 51530533. The reversal of 51530531 is 13503515.

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

It is a cyclic number.

It is not a de Polignac number, because 51530531 - 2¹⁰ = 51529507 is a prime.

It is a super-2 number, since 2×51530531² = 5310791250283922, 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 = 51530497 and 51530506.

It is not an unprimeable number, because it can be changed into a prime (51530533) 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, 1981931 + ... + 1981956.

It is an arithmetic number, because the mean of its divisors is an integer number (13873608).

Almost surely, 2^51530531 is an apocalyptic number.

51530531 is a deficient number, since it is larger than the sum of its proper divisors (3963901).

51530531 is a wasteful number, since it uses less digits than its factorization.

51530531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3963900.

The product of its (nonzero) digits is 1125, while the sum is 23.

The square root of 51530531 is about 7178.4769275940. The cubic root of 51530531 is about 372.1244501138.

The spelling of 51530531 in words is "fifty-one million, five hundred thirty thousand, five hundred thirty-one".