28372840 has 16 divisors (see below), whose sum is σ = 63838980. Its totient is φ = 11349120.

The previous prime is 28372829. The next prime is 28372853. The reversal of 28372840 is 4827382.

28372840 is nontrivially palindromic in base 3.

It can be written as a sum of positive squares in 2 ways, for example, as 26646244 + 1726596 = 5162^2 + 1314^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28372796 and 28372805.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 354621 + ... + 354700.

Almost surely, 2^28372840 is an apocalyptic number.

28372840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28372840 is an abundant number, since it is smaller than the sum of its proper divisors (35466140).

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

28372840 is a wasteful number, since it uses less digits than its factorization.

28372840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709332 (or 709328 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 28372840 is about 5326.6161866611. The cubic root of 28372840 is about 305.0007704003. Note that the first 3 decimals are identical.

The spelling of 28372840 in words is "twenty-eight million, three hundred seventy-two thousand, eight hundred forty".