51564781 has 8 divisors (see below), whose sum is σ = 54952704. Its totient is φ = 48272400.

The previous prime is 51564769. The next prime is 51564797. The reversal of 51564781 is 18746515.

51564781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51564781 - 2⁹ = 51564269 is a prime.

It is a super-2 number, since 2×51564781² = 5317853279155922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51564781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51564701) 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 7 ways as a sum of consecutive naturals, for example, 22770 + ... + 24931.

It is an arithmetic number, because the mean of its divisors is an integer number (6869088).

Almost surely, 2^51564781 is an apocalyptic number.

It is an amenable number.

51564781 is a deficient number, since it is larger than the sum of its proper divisors (3387923).

51564781 is a wasteful number, since it uses less digits than its factorization.

51564781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47771.

The product of its digits is 33600, while the sum is 37.

The square root of 51564781 is about 7180.8621348693. The cubic root of 51564781 is about 372.2068765866.

The spelling of 51564781 in words is "fifty-one million, five hundred sixty-four thousand, seven hundred eighty-one".