51793991 has 4 divisors (see below), whose sum is σ = 51842472. Its totient is φ = 51745512.

The previous prime is 51793961. The next prime is 51793993. The reversal of 51793991 is 19939715.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19939715 = 5 ⋅3987943.

It is a cyclic number.

It is not a de Polignac number, because 51793991 - 2¹⁰ = 51792967 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 (51793993) 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, 22601 + ... + 24786.

It is an arithmetic number, because the mean of its divisors is an integer number (12960618).

Almost surely, 2^51793991 is an apocalyptic number.

51793991 is a deficient number, since it is larger than the sum of its proper divisors (48481).

51793991 is a wasteful number, since it uses less digits than its factorization.

51793991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48480.

The product of its digits is 76545, while the sum is 44.

The square root of 51793991 is about 7196.8042213193. The cubic root of 51793991 is about 372.7575589130.

The spelling of 51793991 in words is "fifty-one million, seven hundred ninety-three thousand, nine hundred ninety-one".