51855815 has 16 divisors (see below), whose sum is σ = 68044320. Its totient is φ = 37624320.

The previous prime is 51855809. The next prime is 51855821.

It is a happy number.

51855815 is nontrivially palindromic in base 10.

51855815 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (51855809) and next prime (51855821).

It is not a de Polignac number, because 51855815 - 2¹² = 51851719 is a prime.

It is a congruent number.

It is an unprimeable number.

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 in 15 ways as a sum of consecutive naturals, for example, 30467 + ... + 32123.

It is an arithmetic number, because the mean of its divisors is an integer number (4252770).

Almost surely, 2^51855815 is an apocalyptic number.

51855815 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

51855815 is a deficient number, since it is larger than the sum of its proper divisors (16188505).

51855815 is a wasteful number, since it uses less digits than its factorization.

51855815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2242.

The product of its digits is 40000, while the sum is 38.

The square root of 51855815 is about 7201.0981801389. The cubic root of 51855815 is about 372.9058142065.

The spelling of 51855815 in words is "fifty-one million, eight hundred fifty-five thousand, eight hundred fifteen".