51388889 has 2 divisors, whose sum is σ = 51388890. Its totient is φ = 51388888.

The previous prime is 51388879. The next prime is 51388891. The reversal of 51388889 is 98888315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46348864 + 5040025 = 6808^2 + 2245^2 .

It is a cyclic number.

It is not a de Polignac number, because 51388889 - 2¹⁶ = 51323353 is a prime.

Together with 51388891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51388879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25694444 + 25694445.

It is an arithmetic number, because the mean of its divisors is an integer number (25694445).

Almost surely, 2^51388889 is an apocalyptic number.

It is an amenable number.

51388889 is a deficient number, since it is larger than the sum of its proper divisors (1).

51388889 is an equidigital number, since it uses as much as digits as its factorization.

51388889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 552960, while the sum is 50.

The square root of 51388889 is about 7168.6043969520. The cubic root of 51388889 is about 371.7831843472.

The spelling of 51388889 in words is "fifty-one million, three hundred eighty-eight thousand, eight hundred eighty-nine".