51690643 has 4 divisors (see below), whose sum is σ = 52398808. Its totient is φ = 50982480.

The previous prime is 51690641. The next prime is 51690649. The reversal of 51690643 is 34609615.

51690643 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 51690643 - 2¹ = 51690641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51690599 and 51690608.

It is not an unprimeable number, because it can be changed into a prime (51690641) 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, 353973 + ... + 354118.

It is an arithmetic number, because the mean of its divisors is an integer number (13099702).

Almost surely, 2^51690643 is an apocalyptic number.

51690643 is a deficient number, since it is larger than the sum of its proper divisors (708165).

51690643 is an equidigital number, since it uses as much as digits as its factorization.

51690643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708164.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 51690643 is about 7189.6205045885. The cubic root of 51690643 is about 372.5094644983.

The spelling of 51690643 in words is "fifty-one million, six hundred ninety thousand, six hundred forty-three".