816279840 has 144 divisors (see below), whose sum is σ = 2795083200. Its totient is φ = 216930816.

The previous prime is 816279811. The next prime is 816279853. The reversal of 816279840 is 48972618.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 516171 + ... + 517749.

It is an arithmetic number, because the mean of its divisors is an integer number (19410300).

Almost surely, 2^816279840 is an apocalyptic number.

816279840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816279840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1397541600).

816279840 is an abundant number, since it is smaller than the sum of its proper divisors (1978803360).

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

816279840 is a wasteful number, since it uses less digits than its factorization.

816279840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1959 (or 1948 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 816279840 is about 28570.6114740304. The cubic root of 816279840 is about 934.5725557229.

The spelling of 816279840 in words is "eight hundred sixteen million, two hundred seventy-nine thousand, eight hundred forty".