816840144 has 30 divisors (see below), whose sum is σ = 2286018306. Its totient is φ = 272280000.

The previous prime is 816840139. The next prime is 816840181. The reversal of 816840144 is 441048618.

It can be written as a sum of positive squares in only one way, i.e., 697593744 + 119246400 = 26412^2 + 10920^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 816840099 and 816840108.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2836107 + ... + 2836394.

Almost surely, 2^816840144 is an apocalyptic number.

It is an amenable number.

816840144 is an abundant number, since it is smaller than the sum of its proper divisors (1469178162).

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

816840144 is a wasteful number, since it uses less digits than its factorization.

816840144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5672515 (or 5672506 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 816840144 is about 28580.4153923627. The cubic root of 816840144 is about 934.7863406486.

The spelling of 816840144 in words is "eight hundred sixteen million, eight hundred forty thousand, one hundred forty-four".