28438940 has 24 divisors (see below), whose sum is σ = 61337472. Its totient is φ = 11067840.

The previous prime is 28438897. The next prime is 28438987. The reversal of 28438940 is 4983482.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28438894 and 28438903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18476 + ... + 19955.

It is an arithmetic number, because the mean of its divisors is an integer number (2555728).

Almost surely, 2^28438940 is an apocalyptic number.

28438940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28438940 is an abundant number, since it is smaller than the sum of its proper divisors (32898532).

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

28438940 is a wasteful number, since it uses less digits than its factorization.

28438940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38477 (or 38475 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 28438940 is about 5332.8172666987. The cubic root of 28438940 is about 305.2374394024.

The spelling of 28438940 in words is "twenty-eight million, four hundred thirty-eight thousand, nine hundred forty".