51456491 has 4 divisors (see below), whose sum is σ = 51504000. Its totient is φ = 51408984.

The previous prime is 51456487. The next prime is 51456499. The reversal of 51456491 is 19465415.

51456491 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 is a cyclic number.

It is not a de Polignac number, because 51456491 - 2² = 51456487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51456499) 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, 22091 + ... + 24308.

It is an arithmetic number, because the mean of its divisors is an integer number (12876000).

Almost surely, 2^51456491 is an apocalyptic number.

51456491 is a deficient number, since it is larger than the sum of its proper divisors (47509).

51456491 is a wasteful number, since it uses less digits than its factorization.

51456491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47508.

The product of its digits is 21600, while the sum is 35.

The square root of 51456491 is about 7173.3179909997. The cubic root of 51456491 is about 371.9461396373.

The spelling of 51456491 in words is "fifty-one million, four hundred fifty-six thousand, four hundred ninety-one".