28821420 has 60 divisors (see below), whose sum is σ = 90418944. Its totient is φ = 7685280.

The previous prime is 28821407. The next prime is 28821427. The reversal of 28821420 is 2412882.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (28821427) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7276 + ... + 10515.

Almost surely, 2^28821420 is an apocalyptic number.

28821420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28821420 is an abundant number, since it is smaller than the sum of its proper divisors (61597524).

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

28821420 is a wasteful number, since it uses less digits than its factorization.

28821420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17812 (or 17801 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 28821420 is about 5368.5584657336. The cubic root of 28821420 is about 306.5997464775.

It can be divided in two parts, 28821 and 420, that added together give a square (29241 = 171²).

The spelling of 28821420 in words is "twenty-eight million, eight hundred twenty-one thousand, four hundred twenty".