51830781 has 16 divisors (see below), whose sum is σ = 71723520. Its totient is φ = 33269040.

The previous prime is 51830777. The next prime is 51830783. The reversal of 51830781 is 18703815.

It is not a de Polignac number, because 51830781 - 2² = 51830777 is a prime.

It is a super-2 number, since 2×51830781² = 5372859718139922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51830783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6330 + ... + 11988.

It is an arithmetic number, because the mean of its divisors is an integer number (4482720).

Almost surely, 2^51830781 is an apocalyptic number.

It is an amenable number.

51830781 is a deficient number, since it is larger than the sum of its proper divisors (19892739).

51830781 is a wasteful number, since it uses less digits than its factorization.

51830781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5776.

The product of its (nonzero) digits is 6720, while the sum is 33.

The square root of 51830781 is about 7199.3597632012. The cubic root of 51830781 is about 372.8457963358.

The spelling of 51830781 in words is "fifty-one million, eight hundred thirty thousand, seven hundred eighty-one".