51640871 has 4 divisors (see below), whose sum is σ = 52516200. Its totient is φ = 50765544.

The previous prime is 51640859. The next prime is 51640873. The reversal of 51640871 is 17804615.

It is a happy number.

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 51640871 - 2¹⁴ = 51624487 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 (51640873) 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, 437576 + ... + 437693.

It is an arithmetic number, because the mean of its divisors is an integer number (13129050).

Almost surely, 2^51640871 is an apocalyptic number.

51640871 is a deficient number, since it is larger than the sum of its proper divisors (875329).

51640871 is an equidigital number, since it uses as much as digits as its factorization.

51640871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875328.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 51640871 is about 7186.1582921614. The cubic root of 51640871 is about 372.3898651927.

The spelling of 51640871 in words is "fifty-one million, six hundred forty thousand, eight hundred seventy-one".