55816815 has 16 divisors (see below), whose sum is σ = 89399808. Its totient is φ = 29738016.

The previous prime is 55816811. The next prime is 55816819. The reversal of 55816815 is 51861855.

It is an interprime number because it is at equal distance from previous prime (55816811) and next prime (55816819).

It is not a de Polignac number, because 55816815 - 2² = 55816811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55816811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25702 + ... + 27788.

It is an arithmetic number, because the mean of its divisors is an integer number (5587488).

Almost surely, 2^55816815 is an apocalyptic number.

55816815 is a deficient number, since it is larger than the sum of its proper divisors (33582993).

55816815 is a wasteful number, since it uses less digits than its factorization.

55816815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3878.

The product of its digits is 48000, while the sum is 39.

The square root of 55816815 is about 7471.0651850991. The cubic root of 55816815 is about 382.1686138303.

The spelling of 55816815 in words is "fifty-five million, eight hundred sixteen thousand, eight hundred fifteen".