28684340 has 12 divisors (see below), whose sum is σ = 60237156. Its totient is φ = 11473728.

The previous prime is 28684333. The next prime is 28684349. The reversal of 28684340 is 4348682.

It can be written as a sum of positive squares in 2 ways, for example, as 8145316 + 20539024 = 2854^2 + 4532^2 .

It is a super-2 number, since 2×28684340² = 1645582722471200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28684340.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28684349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 717089 + ... + 717128.

It is an arithmetic number, because the mean of its divisors is an integer number (5019763).

Almost surely, 2^28684340 is an apocalyptic number.

28684340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28684340 is an abundant number, since it is smaller than the sum of its proper divisors (31552816).

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

28684340 is a wasteful number, since it uses less digits than its factorization.

28684340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434226 (or 1434224 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 35.

The square root of 28684340 is about 5355.7763209455. The cubic root of 28684340 is about 306.1128921177.

The spelling of 28684340 in words is "twenty-eight million, six hundred eighty-four thousand, three hundred forty".