51040091 has 4 divisors (see below), whose sum is σ = 51123432. Its totient is φ = 50956752.

The previous prime is 51040081. The next prime is 51040127. The reversal of 51040091 is 19004015.

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 51040091 - 2¹⁰ = 51039067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51040021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40745 + ... + 41978.

It is an arithmetic number, because the mean of its divisors is an integer number (12780858).

Almost surely, 2^51040091 is an apocalyptic number.

51040091 is a deficient number, since it is larger than the sum of its proper divisors (83341).

51040091 is an equidigital number, since it uses as much as digits as its factorization.

51040091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83340.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 51040091 is about 7144.2348085712. The cubic root of 51040091 is about 370.9401244542.

The spelling of 51040091 in words is "fifty-one million, forty thousand, ninety-one".