51549561 has 32 divisors (see below), whose sum is σ = 89323520. Its totient is φ = 28767312.

The previous prime is 51549551. The next prime is 51549569. The reversal of 51549561 is 16594515.

51549561 is a `hidden beast` number, since 51 + 5 + 49 + 561 = 666.

51549561 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 51549561 - 2¹⁰ = 51548537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51549569) 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 31 ways as a sum of consecutive naturals, for example, 4956 + ... + 11298.

It is an arithmetic number, because the mean of its divisors is an integer number (2791360).

Almost surely, 2^51549561 is an apocalyptic number.

It is an amenable number.

51549561 is a deficient number, since it is larger than the sum of its proper divisors (37773959).

51549561 is a wasteful number, since it uses less digits than its factorization.

51549561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6402 (or 6396 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The square root of 51549561 is about 7179.8022953282. The cubic root of 51549561 is about 372.1702524540.

The spelling of 51549561 in words is "fifty-one million, five hundred forty-nine thousand, five hundred sixty-one".