28520940 has 144 divisors (see below), whose sum is σ = 94802400. Its totient is φ = 6386688.

The previous prime is 28520939. The next prime is 28520941. The reversal of 28520940 is 4902582.

It is an interprime number because it is at equal distance from previous prime (28520939) and next prime (28520941).

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

It is a junction number, because it is equal to n+sod(n) for n = 28520898 and 28520907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28520941) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 261606 + ... + 261714.

It is an arithmetic number, because the mean of its divisors is an integer number (658350).

Almost surely, 2^28520940 is an apocalyptic number.

28520940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is a pronic number, being equal to 5340×5341.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28520940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47401200).

28520940 is an abundant number, since it is smaller than the sum of its proper divisors (66281460).

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

28520940 is a wasteful number, since it uses less digits than its factorization.

28520940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 28520940 is about 5340.4999765940. The cubic root of 28520940 is about 305.5305287614.

The spelling of 28520940 in words is "twenty-eight million, five hundred twenty thousand, nine hundred forty".