818615440 has 20 divisors (see below), whose sum is σ = 1903281084. Its totient is φ = 327446144.

The previous prime is 818615429. The next prime is 818615461. The reversal of 818615440 is 44516818.

It can be written as a sum of positive squares in 2 ways, for example, as 492307344 + 326308096 = 22188^2 + 18064^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 818615440.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5116267 + ... + 5116426.

Almost surely, 2^818615440 is an apocalyptic number.

818615440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

818615440 is an abundant number, since it is smaller than the sum of its proper divisors (1084665644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

818615440 is a wasteful number, since it uses less digits than its factorization.

818615440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10232706 (or 10232700 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 37.

The square root of 818615440 is about 28611.4564466753. The cubic root of 818615440 is about 935.4630628775.

The spelling of 818615440 in words is "eight hundred eighteen million, six hundred fifteen thousand, four hundred forty".