51072391 has 2 divisors, whose sum is σ = 51072392. Its totient is φ = 51072390.

The previous prime is 51072349. The next prime is 51072449. The reversal of 51072391 is 19327015.

51072391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51072391 - 2¹¹ = 51070343 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51072331) 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 as a sum of consecutive naturals, namely, 25536195 + 25536196.

It is an arithmetic number, because the mean of its divisors is an integer number (25536196).

Almost surely, 2^51072391 is an apocalyptic number.

51072391 is a deficient number, since it is larger than the sum of its proper divisors (1).

51072391 is an equidigital number, since it uses as much as digits as its factorization.

51072391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 51072391 is about 7146.4950150406. The cubic root of 51072391 is about 371.0183560252.

The spelling of 51072391 in words is "fifty-one million, seventy-two thousand, three hundred ninety-one".