51000691 has 4 divisors (see below), whose sum is σ = 58286512. Its totient is φ = 43714872.

The previous prime is 51000667. The next prime is 51000707. The reversal of 51000691 is 19600015.

51000691 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, and also an emirpimes, since its reverse is a distinct semiprime: 19600015 = 5 ⋅3920003.

It is a cyclic number.

It is not a de Polignac number, because 51000691 - 2⁵ = 51000659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51000641) 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, 3642900 + ... + 3642913.

It is an arithmetic number, because the mean of its divisors is an integer number (14571628).

Almost surely, 2^51000691 is an apocalyptic number.

51000691 is a deficient number, since it is larger than the sum of its proper divisors (7285821).

51000691 is an equidigital number, since it uses as much as digits as its factorization.

51000691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7285820.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 51000691 is about 7141.4768080559. The cubic root of 51000691 is about 370.8446517720.

The spelling of 51000691 in words is "fifty-one million, six hundred ninety-one", and thus it is an aban number.