51778109 has 2 divisors, whose sum is σ = 51778110. Its totient is φ = 51778108.

The previous prime is 51778093. The next prime is 51778117. The reversal of 51778109 is 90187715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30415225 + 21362884 = 5515^2 + 4622^2 .

It is a cyclic number.

It is not a de Polignac number, because 51778109 - 2⁴ = 51778093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51778169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25889054 + 25889055.

It is an arithmetic number, because the mean of its divisors is an integer number (25889055).

Almost surely, 2^51778109 is an apocalyptic number.

It is an amenable number.

51778109 is a deficient number, since it is larger than the sum of its proper divisors (1).

51778109 is an equidigital number, since it uses as much as digits as its factorization.

51778109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 38.

The square root of 51778109 is about 7195.7007302972. The cubic root of 51778109 is about 372.7194544878.

The spelling of 51778109 in words is "fifty-one million, seven hundred seventy-eight thousand, one hundred nine".