51209897 has 2 divisors, whose sum is σ = 51209898. Its totient is φ = 51209896.

The previous prime is 51209869. The next prime is 51209941. The reversal of 51209897 is 79890215.

51209897 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49294441 + 1915456 = 7021^2 + 1384^2 .

It is a cyclic number.

It is not a de Polignac number, because 51209897 - 2⁶ = 51209833 is a prime.

It is not a weakly prime, because it can be changed into another prime (51209867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25604948 + 25604949.

It is an arithmetic number, because the mean of its divisors is an integer number (25604949).

Almost surely, 2^51209897 is an apocalyptic number.

It is an amenable number.

51209897 is a deficient number, since it is larger than the sum of its proper divisors (1).

51209897 is an equidigital number, since it uses as much as digits as its factorization.

51209897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 51209897 is about 7156.1090684813. The cubic root of 51209897 is about 371.3510310875.

The spelling of 51209897 in words is "fifty-one million, two hundred nine thousand, eight hundred ninety-seven".