51391393 has 8 divisors (see below), whose sum is σ = 53251200. Its totient is φ = 49537488.

The previous prime is 51391387. The next prime is 51391421. The reversal of 51391393 is 39319315.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51391393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51391313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23880 + ... + 25942.

It is an arithmetic number, because the mean of its divisors is an integer number (6656400).

Almost surely, 2^51391393 is an apocalyptic number.

It is an amenable number.

51391393 is a deficient number, since it is larger than the sum of its proper divisors (1859807).

51391393 is a wasteful number, since it uses less digits than its factorization.

51391393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2951.

The product of its digits is 10935, while the sum is 34.

The square root of 51391393 is about 7168.7790452768. The cubic root of 51391393 is about 371.7892228119.

The spelling of 51391393 in words is "fifty-one million, three hundred ninety-one thousand, three hundred ninety-three".