51505261 has 4 divisors (see below), whose sum is σ = 51522300. Its totient is φ = 51488224.

The previous prime is 51505213. The next prime is 51505273. The reversal of 51505261 is 16250515.

51505261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 13003236 + 38502025 = 3606^2 + 6205^2 .

It is a cyclic number.

It is not a de Polignac number, because 51505261 - 2¹¹ = 51503213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51506261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2626 + ... + 10483.

It is an arithmetic number, because the mean of its divisors is an integer number (12880575).

Almost surely, 2^51505261 is an apocalyptic number.

It is an amenable number.

51505261 is a deficient number, since it is larger than the sum of its proper divisors (17039).

51505261 is a wasteful number, since it uses less digits than its factorization.

51505261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17038.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 51505261 is about 7176.7165890817. The cubic root of 51505261 is about 372.0636116023.

Adding to 51505261 its reverse (16250515), we get a palindrome (67755776).

The spelling of 51505261 in words is "fifty-one million, five hundred five thousand, two hundred sixty-one".