51421817 has 2 divisors, whose sum is σ = 51421818. Its totient is φ = 51421816.

The previous prime is 51421789. The next prime is 51421861. The reversal of 51421817 is 71812415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36529936 + 14891881 = 6044^2 + 3859^2 .

It is a cyclic number.

It is not a de Polignac number, because 51421817 - 2¹⁶ = 51356281 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51421817.

It is not a weakly prime, because it can be changed into another prime (51421217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25710908 + 25710909.

It is an arithmetic number, because the mean of its divisors is an integer number (25710909).

Almost surely, 2^51421817 is an apocalyptic number.

It is an amenable number.

51421817 is a deficient number, since it is larger than the sum of its proper divisors (1).

51421817 is an equidigital number, since it uses as much as digits as its factorization.

51421817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2240, while the sum is 29.

The square root of 51421817 is about 7170.9007105105. The cubic root of 51421817 is about 371.8625754576.

The spelling of 51421817 in words is "fifty-one million, four hundred twenty-one thousand, eight hundred seventeen".