28990020 has 24 divisors (see below), whose sum is σ = 81172224. Its totient is φ = 7730656.

The previous prime is 28990019. The next prime is 28990021. The reversal of 28990020 is 2009982.

It is an interprime number because it is at equal distance from previous prime (28990019) and next prime (28990021).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 28990020.

It is not an unprimeable number, because it can be changed into a prime (28990021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241524 + ... + 241643.

It is an arithmetic number, because the mean of its divisors is an integer number (3382176).

Almost surely, 2^28990020 is an apocalyptic number.

28990020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28990020 is an abundant number, since it is smaller than the sum of its proper divisors (52182204).

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

28990020 is a wasteful number, since it uses less digits than its factorization.

28990020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483179 (or 483177 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 28990020 is about 5384.2381076620. The cubic root of 28990020 is about 307.1964351664.

It can be divided in two parts, 289 and 90020, that added together give a palindrome (90309).

The spelling of 28990020 in words is "twenty-eight million, nine hundred ninety thousand, twenty".