51316991 has 8 divisors (see below), whose sum is σ = 56657664. Its totient is φ = 46088920.

The previous prime is 51316981. The next prime is 51317003. The reversal of 51316991 is 19961315.

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

It is a cyclic number.

It is not a de Polignac number, because 51316991 - 2⁶ = 51316927 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 (51316981) 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, 27191 + ... + 29016.

It is an arithmetic number, because the mean of its divisors is an integer number (7082208).

Almost surely, 2^51316991 is an apocalyptic number.

51316991 is a deficient number, since it is larger than the sum of its proper divisors (5340673).

51316991 is a wasteful number, since it uses less digits than its factorization.

51316991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56301.

The product of its digits is 7290, while the sum is 35.

The square root of 51316991 is about 7163.5878580499. The cubic root of 51316991 is about 371.6097166076.

The spelling of 51316991 in words is "fifty-one million, three hundred sixteen thousand, nine hundred ninety-one".