51644623 has 4 divisors (see below), whose sum is σ = 54682560. Its totient is φ = 48606688.

The previous prime is 51644617. The next prime is 51644651. The reversal of 51644623 is 32644615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32644615 = 5 ⋅6528923.

It is a cyclic number.

It is not a de Polignac number, because 51644623 - 2⁹ = 51644111 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 (51644323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1518943 + ... + 1518976.

It is an arithmetic number, because the mean of its divisors is an integer number (13670640).

Almost surely, 2^51644623 is an apocalyptic number.

51644623 is a deficient number, since it is larger than the sum of its proper divisors (3037937).

51644623 is a wasteful number, since it uses less digits than its factorization.

51644623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3037936.

The product of its digits is 17280, while the sum is 31.

The square root of 51644623 is about 7186.4193448476. The cubic root of 51644623 is about 372.3988837143.

The spelling of 51644623 in words is "fifty-one million, six hundred forty-four thousand, six hundred twenty-three".