51087749 has 4 divisors (see below), whose sum is σ = 51102060. Its totient is φ = 51073440.

The previous prime is 51087733. The next prime is 51087791. The reversal of 51087749 is 94778015.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 36784225 + 14303524 = 6065^2 + 3782^2 .

It is a cyclic number.

It is not a de Polignac number, because 51087749 - 2⁴ = 51087733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51087709) 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, 3089 + ... + 10569.

It is an arithmetic number, because the mean of its divisors is an integer number (12775515).

Almost surely, 2^51087749 is an apocalyptic number.

It is an amenable number.

51087749 is a deficient number, since it is larger than the sum of its proper divisors (14311).

51087749 is an equidigital number, since it uses as much as digits as its factorization.

51087749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14310.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 51087749 is about 7147.5694470218. The cubic root of 51087749 is about 371.0555419929.

The spelling of 51087749 in words is "fifty-one million, eighty-seven thousand, seven hundred forty-nine".