51947993 has 4 divisors (see below), whose sum is σ = 52039860. Its totient is φ = 51856128.

The previous prime is 51947977. The next prime is 51948011. The reversal of 51947993 is 39974915.

51947993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16581184 + 35366809 = 4072^2 + 5947^2 .

It is a cyclic number.

It is not a de Polignac number, because 51947993 - 2⁴ = 51947977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51947893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45080 + ... + 46217.

It is an arithmetic number, because the mean of its divisors is an integer number (13009965).

Almost surely, 2^51947993 is an apocalyptic number.

It is an amenable number.

51947993 is a deficient number, since it is larger than the sum of its proper divisors (91867).

51947993 is an equidigital number, since it uses as much as digits as its factorization.

51947993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91866.

The product of its digits is 306180, while the sum is 47.

The square root of 51947993 is about 7207.4956122082. The cubic root of 51947993 is about 373.1266403881.

The spelling of 51947993 in words is "fifty-one million, nine hundred forty-seven thousand, nine hundred ninety-three".