51532561 has 4 divisors (see below), whose sum is σ = 51671092. Its totient is φ = 51394032.

The previous prime is 51532553. The next prime is 51532567. The reversal of 51532561 is 16523515.

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 16248961 + 35283600 = 4031^2 + 5940^2 .

It is a cyclic number.

It is not a de Polignac number, because 51532561 - 2³ = 51532553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51532567) 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, 68706 + ... + 69451.

It is an arithmetic number, because the mean of its divisors is an integer number (12917773).

Almost surely, 2^51532561 is an apocalyptic number.

It is an amenable number.

51532561 is a deficient number, since it is larger than the sum of its proper divisors (138531).

51532561 is a wasteful number, since it uses less digits than its factorization.

51532561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138530.

The product of its digits is 4500, while the sum is 28.

The square root of 51532561 is about 7178.6183210977. The cubic root of 51532561 is about 372.1293365549.

The spelling of 51532561 in words is "fifty-one million, five hundred thirty-two thousand, five hundred sixty-one".