51781673 has 2 divisors, whose sum is σ = 51781674. Its totient is φ = 51781672.

The previous prime is 51781621. The next prime is 51781703. The reversal of 51781673 is 37618715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35200489 + 16581184 = 5933^2 + 4072^2 .

It is a cyclic number.

It is not a de Polignac number, because 51781673 - 2²⁴ = 35004457 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51781603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25890836 + 25890837.

It is an arithmetic number, because the mean of its divisors is an integer number (25890837).

Almost surely, 2^51781673 is an apocalyptic number.

It is an amenable number.

51781673 is a deficient number, since it is larger than the sum of its proper divisors (1).

51781673 is an equidigital number, since it uses as much as digits as its factorization.

51781673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 38.

The square root of 51781673 is about 7195.9483739115. The cubic root of 51781673 is about 372.7280059889.

The spelling of 51781673 in words is "fifty-one million, seven hundred eighty-one thousand, six hundred seventy-three".