815438385 has 48 divisors (see below), whose sum is σ = 1473161040. Its totient is φ = 416747520.

The previous prime is 815438383. The next prime is 815438387. The reversal of 815438385 is 583834518.

It is an interprime number because it is at equal distance from previous prime (815438383) and next prime (815438387).

It can be written as a sum of positive squares in 8 ways, for example, as 7969329 + 807469056 = 2823^2 + 28416^2 .

It is not a de Polignac number, because 815438385 - 2¹ = 815438383 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 815438385.

It is not an unprimeable number, because it can be changed into a prime (815438383) 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 in 47 ways as a sum of consecutive naturals, for example, 176505 + ... + 181065.

It is an arithmetic number, because the mean of its divisors is an integer number (30690855).

Almost surely, 2^815438385 is an apocalyptic number.

It is an amenable number.

815438385 is a deficient number, since it is larger than the sum of its proper divisors (657722655).

815438385 is a wasteful number, since it uses less digits than its factorization.

815438385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4738 (or 4735 counting only the distinct ones).

The product of its digits is 460800, while the sum is 45.

The square root of 815438385 is about 28555.8817934239. The cubic root of 815438385 is about 934.2513133072.

The spelling of 815438385 in words is "eight hundred fifteen million, four hundred thirty-eight thousand, three hundred eighty-five".