28521438 has 16 divisors (see below), whose sum is σ = 62228736. Its totient is φ = 8642840.

The previous prime is 28521419. The next prime is 28521443. The reversal of 28521438 is 83412582.

It is a super-3 number, since 3×28521438³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 28521399 and 28521408.

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, 216006 + ... + 216137.

It is an arithmetic number, because the mean of its divisors is an integer number (3889296).

Almost surely, 2^28521438 is an apocalyptic number.

28521438 is an abundant number, since it is smaller than the sum of its proper divisors (33707298).

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

28521438 is a wasteful number, since it uses less digits than its factorization.

28521438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432159.

The product of its digits is 15360, while the sum is 33.

The square root of 28521438 is about 5340.5466012385. The cubic root of 28521438 is about 305.5323070258.

The spelling of 28521438 in words is "twenty-eight million, five hundred twenty-one thousand, four hundred thirty-eight".