51047891 has 2 divisors, whose sum is σ = 51047892. Its totient is φ = 51047890.

The previous prime is 51047873. The next prime is 51047929. The reversal of 51047891 is 19874015.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51047891 is a prime.

It is not a weakly prime, because it can be changed into another prime (51049891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25523945 + 25523946.

It is an arithmetic number, because the mean of its divisors is an integer number (25523946).

Almost surely, 2^51047891 is an apocalyptic number.

51047891 is a deficient number, since it is larger than the sum of its proper divisors (1).

51047891 is an equidigital number, since it uses as much as digits as its factorization.

51047891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 51047891 is about 7144.7806824283. The cubic root of 51047891 is about 370.9590193108.

The spelling of 51047891 in words is "fifty-one million, forty-seven thousand, eight hundred ninety-one".