51689887 has 2 divisors, whose sum is σ = 51689888. Its totient is φ = 51689886.

The previous prime is 51689879. The next prime is 51689903. The reversal of 51689887 is 78898615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51689887 - 2³ = 51689879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51689857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25844943 + 25844944.

It is an arithmetic number, because the mean of its divisors is an integer number (25844944).

Almost surely, 2^51689887 is an apocalyptic number.

51689887 is a deficient number, since it is larger than the sum of its proper divisors (1).

51689887 is an equidigital number, since it uses as much as digits as its factorization.

51689887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 967680, while the sum is 52.

The square root of 51689887 is about 7189.5679286032. The cubic root of 51689887 is about 372.5076484474.

The spelling of 51689887 in words is "fifty-one million, six hundred eighty-nine thousand, eight hundred eighty-seven".