51816815 has 8 divisors (see below), whose sum is σ = 64883808. Its totient is φ = 39651040.

The previous prime is 51816803. The next prime is 51816847. The reversal of 51816815 is 51861815.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51816815 - 2¹⁴ = 51800431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 225176 + ... + 225405.

It is an arithmetic number, because the mean of its divisors is an integer number (8110476).

Almost surely, 2^51816815 is an apocalyptic number.

51816815 is a deficient number, since it is larger than the sum of its proper divisors (13066993).

51816815 is a wasteful number, since it uses less digits than its factorization.

51816815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450609.

The product of its digits is 9600, while the sum is 35.

The square root of 51816815 is about 7198.3897504928. The cubic root of 51816815 is about 372.8123050908.

The spelling of 51816815 in words is "fifty-one million, eight hundred sixteen thousand, eight hundred fifteen".