51389787 has 4 divisors (see below), whose sum is σ = 68519720. Its totient is φ = 34259856.

The previous prime is 51389783. The next prime is 51389803. The reversal of 51389787 is 78798315.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51389787 - 2² = 51389783 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51389783) 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, 8564962 + ... + 8564967.

It is an arithmetic number, because the mean of its divisors is an integer number (17129930).

Almost surely, 2^51389787 is an apocalyptic number.

51389787 is a deficient number, since it is larger than the sum of its proper divisors (17129933).

51389787 is a wasteful number, since it uses less digits than its factorization.

51389787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17129932.

The product of its digits is 423360, while the sum is 48.

The square root of 51389787 is about 7168.6670309061. The cubic root of 51389787 is about 371.7853499214.

The spelling of 51389787 in words is "fifty-one million, three hundred eighty-nine thousand, seven hundred eighty-seven".