51251663 has 4 divisors (see below), whose sum is σ = 51620520. Its totient is φ = 50882808.

The previous prime is 51251647. The next prime is 51251687. The reversal of 51251663 is 36615215.

51251663 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 is a cyclic number.

It is not a de Polignac number, because 51251663 - 2⁴ = 51251647 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 (51251633) 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, 184220 + ... + 184497.

It is an arithmetic number, because the mean of its divisors is an integer number (12905130).

Almost surely, 2^51251663 is an apocalyptic number.

51251663 is a deficient number, since it is larger than the sum of its proper divisors (368857).

51251663 is a wasteful number, since it uses less digits than its factorization.

51251663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368856.

The product of its digits is 5400, while the sum is 29.

The square root of 51251663 is about 7159.0266796542. The cubic root of 51251663 is about 371.4519597065.

Adding to 51251663 its reverse (36615215), we get a palindrome (87866878).

The spelling of 51251663 in words is "fifty-one million, two hundred fifty-one thousand, six hundred sixty-three".