51985217 has 2 divisors, whose sum is σ = 51985218. Its totient is φ = 51985216.

The previous prime is 51985211. The next prime is 51985229. The reversal of 51985217 is 71258915.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42523441 + 9461776 = 6521^2 + 3076^2 .

It is a cyclic number.

It is not a de Polignac number, because 51985217 - 2²² = 47790913 is a prime.

It is not a weakly prime, because it can be changed into another prime (51985211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25992608 + 25992609.

It is an arithmetic number, because the mean of its divisors is an integer number (25992609).

Almost surely, 2^51985217 is an apocalyptic number.

It is an amenable number.

51985217 is a deficient number, since it is larger than the sum of its proper divisors (1).

51985217 is an equidigital number, since it uses as much as digits as its factorization.

51985217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25200, while the sum is 38.

The square root of 51985217 is about 7210.0774614424. The cubic root of 51985217 is about 373.2157420009.

The spelling of 51985217 in words is "fifty-one million, nine hundred eighty-five thousand, two hundred seventeen".