51421217 has 2 divisors, whose sum is σ = 51421218. Its totient is φ = 51421216.

The previous prime is 51421213. The next prime is 51421229. The reversal of 51421217 is 71212415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30481441 + 20939776 = 5521^2 + 4576^2 .

It is a cyclic number.

It is not a de Polignac number, because 51421217 - 2² = 51421213 is a prime.

It is a super-2 number, since 2×51421217² = 5288283115522178, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 51421192 and 51421201.

It is not a weakly prime, because it can be changed into another prime (51421213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25710608 + 25710609.

It is an arithmetic number, because the mean of its divisors is an integer number (25710609).

Almost surely, 2^51421217 is an apocalyptic number.

It is an amenable number.

51421217 is a deficient number, since it is larger than the sum of its proper divisors (1).

51421217 is an equidigital number, since it uses as much as digits as its factorization.

51421217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 560, while the sum is 23.

The square root of 51421217 is about 7170.8588746398. The cubic root of 51421217 is about 371.8611291298.

The spelling of 51421217 in words is "fifty-one million, four hundred twenty-one thousand, two hundred seventeen".