51779209 has 2 divisors, whose sum is σ = 51779210. Its totient is φ = 51779208.

The previous prime is 51779183. The next prime is 51779219. The reversal of 51779209 is 90297715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43599609 + 8179600 = 6603^2 + 2860^2 .

It is a cyclic number.

It is not a de Polignac number, because 51779209 - 2¹⁹ = 51254921 is a prime.

It is not a weakly prime, because it can be changed into another prime (51779219) 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, 25889604 + 25889605.

It is an arithmetic number, because the mean of its divisors is an integer number (25889605).

Almost surely, 2^51779209 is an apocalyptic number.

It is an amenable number.

51779209 is a deficient number, since it is larger than the sum of its proper divisors (1).

51779209 is an equidigital number, since it uses as much as digits as its factorization.

51779209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39690, while the sum is 40.

The square root of 51779209 is about 7195.7771644208. Note that the first 3 decimals coincide. The cubic root of 51779209 is about 372.7220938819.

The spelling of 51779209 in words is "fifty-one million, seven hundred seventy-nine thousand, two hundred nine".