51187693 has 4 divisors (see below), whose sum is σ = 51202368. Its totient is φ = 51173020.

The previous prime is 51187681. The next prime is 51187699. The reversal of 51187693 is 39678115.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 39678115 = 5 ⋅7935623.

It is a cyclic number.

It is not a de Polignac number, because 51187693 - 2²¹ = 49090541 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51187699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1230 + ... + 10192.

It is an arithmetic number, because the mean of its divisors is an integer number (12800592).

It is a vampire number, since it can be written as 5711 ⋅ 8963 (with its own digits).

Almost surely, 2^51187693 is an apocalyptic number.

It is an amenable number.

51187693 is a deficient number, since it is larger than the sum of its proper divisors (14675).

51187693 is an equidigital number, since it uses as much as digits as its factorization.

51187693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14674.

The product of its digits is 45360, while the sum is 40.

The square root of 51187693 is about 7154.5574985459. The cubic root of 51187693 is about 371.2973522039.

The spelling of 51187693 in words is "fifty-one million, one hundred eighty-seven thousand, six hundred ninety-three".