51531521 has 8 divisors (see below), whose sum is σ = 53809920. Its totient is φ = 49286608.

The previous prime is 51531511. The next prime is 51531527. The reversal of 51531521 is 12513515.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51531521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51531527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5201 + ... + 11406.

It is an arithmetic number, because the mean of its divisors is an integer number (6726240).

Almost surely, 2^51531521 is an apocalyptic number.

It is an amenable number.

51531521 is a deficient number, since it is larger than the sum of its proper divisors (2278399).

51531521 is a wasteful number, since it uses less digits than its factorization.

51531521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16743.

The product of its digits is 750, while the sum is 23.

The square root of 51531521 is about 7178.5458833945. The cubic root of 51531521 is about 372.1268331726.

The spelling of 51531521 in words is "fifty-one million, five hundred thirty-one thousand, five hundred twenty-one".