28038240 has 72 divisors (see below), whose sum is σ = 95685408. Its totient is φ = 7476480.

The previous prime is 28038239. The next prime is 28038247. The reversal of 28038240 is 4283082.

28038240 is a `hidden beast` number, since 280 + 382 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×28038240² = 1572285804595200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28038247) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8296 + ... + 11175.

It is an arithmetic number, because the mean of its divisors is an integer number (1328964).

Almost surely, 2^28038240 is an apocalyptic number.

28038240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28038240 is an abundant number, since it is smaller than the sum of its proper divisors (67647168).

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

28038240 is a wasteful number, since it uses less digits than its factorization.

28038240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19492 (or 19481 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 28038240 is about 5295.1147296352. The cubic root of 28038240 is about 303.7970714024.

The spelling of 28038240 in words is "twenty-eight million, thirty-eight thousand, two hundred forty".