279728640 has 400 divisors, whose sum is σ = 1069485120. Its totient is φ = 69672960.

The previous prime is 279728633. The next prime is 279728653. The reversal of 279728640 is 46827972.

It is a super-2 number, since 2×279728640² = 156496224072499200, which contains 22 as substring.

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 39 ways as a sum of consecutive naturals, for example, 3939805 + ... + 3939875.

Almost surely, 2^279728640 is an apocalyptic number.

279728640 is a gapful number since it is divisible by the number (20) 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 279728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (534742560).

279728640 is an abundant number, since it is smaller than the sum of its proper divisors (789756480).

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

279728640 is an equidigital number, since it uses as much as digits as its factorization.

279728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 279728640 is about 16725.0901342863. The cubic root of 279728640 is about 654.0018516907.

The spelling of 279728640 in words is "two hundred seventy-nine million, seven hundred twenty-eight thousand, six hundred forty".