51506263 has 4 divisors (see below), whose sum is σ = 52016328. Its totient is φ = 50996200.

The previous prime is 51506261. The next prime is 51506267. The reversal of 51506263 is 36260515.

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 51506263 - 2¹ = 51506261 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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254881 + ... + 255082.

It is an arithmetic number, because the mean of its divisors is an integer number (13004082).

Almost surely, 2^51506263 is an apocalyptic number.

51506263 is a deficient number, since it is larger than the sum of its proper divisors (510065).

51506263 is a wasteful number, since it uses less digits than its factorization.

51506263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510064.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 51506263 is about 7176.7863978246. The cubic root of 51506263 is about 372.0660243353.

Adding to 51506263 its reverse (36260515), we get a palindrome (87766778).

The spelling of 51506263 in words is "fifty-one million, five hundred six thousand, two hundred sixty-three".