51695989 has 2 divisors, whose sum is σ = 51695990. Its totient is φ = 51695988.

The previous prime is 51695983. The next prime is 51696049. The reversal of 51695989 is 98959615.

51695989 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., 45024100 + 6671889 = 6710^2 + 2583^2 .

It is a cyclic number.

It is not a de Polignac number, because 51695989 - 2³ = 51695981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51695981) 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, 25847994 + 25847995.

It is an arithmetic number, because the mean of its divisors is an integer number (25847995).

Almost surely, 2^51695989 is an apocalyptic number.

It is an amenable number.

51695989 is a deficient number, since it is larger than the sum of its proper divisors (1).

51695989 is an equidigital number, since it uses as much as digits as its factorization.

51695989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 874800, while the sum is 52.

The square root of 51695989 is about 7189.9922809416. The cubic root of 51695989 is about 372.5223060678.

The spelling of 51695989 in words is "fifty-one million, six hundred ninety-five thousand, nine hundred eighty-nine".