51221745 has 24 divisors (see below), whose sum is σ = 89294400. Its totient is φ = 27161376.

The previous prime is 51221741. The next prime is 51221771. The reversal of 51221745 is 54712215.

51221745 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51221745 - 2² = 51221741 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51221741) 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 23 ways as a sum of consecutive naturals, for example, 4876 + ... + 11234.

It is an arithmetic number, because the mean of its divisors is an integer number (3720600).

Almost surely, 2^51221745 is an apocalyptic number.

It is an amenable number.

51221745 is a deficient number, since it is larger than the sum of its proper divisors (38072655).

51221745 is a wasteful number, since it uses less digits than its factorization.

51221745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6549 (or 6546 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 51221745 is about 7156.9368447682. The cubic root of 51221745 is about 371.3796676598.

The spelling of 51221745 in words is "fifty-one million, two hundred twenty-one thousand, seven hundred forty-five".