51181633 has 4 divisors (see below), whose sum is σ = 51266560. Its totient is φ = 51096708.

The previous prime is 51181597. The next prime is 51181639. The reversal of 51181633 is 33618115.

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, and also an emirpimes, since its reverse is a distinct semiprime: 33618115 = 5 ⋅6723623.

It is a cyclic number.

It is not a de Polignac number, because 51181633 - 2⁹ = 51181121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51181639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41553 + ... + 42766.

It is an arithmetic number, because the mean of its divisors is an integer number (12816640).

Almost surely, 2^51181633 is an apocalyptic number.

It is an amenable number.

51181633 is a deficient number, since it is larger than the sum of its proper divisors (84927).

51181633 is an equidigital number, since it uses as much as digits as its factorization.

51181633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84926.

The product of its digits is 2160, while the sum is 28.

The square root of 51181633 is about 7154.1339797351. The cubic root of 51181633 is about 371.2826992628.

Adding to 51181633 its reverse (33618115), we get a palindrome (84799748).

The spelling of 51181633 in words is "fifty-one million, one hundred eighty-one thousand, six hundred thirty-three".