51181637609 has 4 divisors (see below), whose sum is σ = 51678546816. Its totient is φ = 50684728404.

The previous prime is 51181637567. The next prime is 51181637621. The reversal of 51181637609 is 90673618115.

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.

It is a cyclic number.

It is not a de Polignac number, because 51181637609 - 2²⁴ = 51164860393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51181637009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248454449 + ... + 248454654.

It is an arithmetic number, because the mean of its divisors is an integer number (12919636704).

Almost surely, 2^51181637609 is an apocalyptic number.

It is an amenable number.

51181637609 is a deficient number, since it is larger than the sum of its proper divisors (496909207).

51181637609 is a wasteful number, since it uses less digits than its factorization.

51181637609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496909206.

The product of its (nonzero) digits is 272160, while the sum is 47.

The spelling of 51181637609 in words is "fifty-one billion, one hundred eighty-one million, six hundred thirty-seven thousand, six hundred nine".