51784381 has 4 divisors (see below), whose sum is σ = 56492064. Its totient is φ = 47076700.

The previous prime is 51784379. The next prime is 51784387. The reversal of 51784381 is 18348715.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51784381 - 2¹ = 51784379 is a prime.

It is a super-2 number, since 2×51784381² = 5363244231106322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51784381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51784387) 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, 2353825 + ... + 2353846.

It is an arithmetic number, because the mean of its divisors is an integer number (14123016).

Almost surely, 2^51784381 is an apocalyptic number.

It is an amenable number.

51784381 is a deficient number, since it is larger than the sum of its proper divisors (4707683).

51784381 is a wasteful number, since it uses less digits than its factorization.

51784381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4707682.

The product of its digits is 26880, while the sum is 37.

The square root of 51784381 is about 7196.1365328904. The cubic root of 51784381 is about 372.7345033317.

It can be divided in two parts, 5178 and 4381, that added together give a palindrome (9559).

The spelling of 51784381 in words is "fifty-one million, seven hundred eighty-four thousand, three hundred eighty-one".