28553820 has 24 divisors (see below), whose sum is σ = 79950864. Its totient is φ = 7614336.

The previous prime is 28553809. The next prime is 28553831. The reversal of 28553820 is 2835582.

It is an interprime number because it is at equal distance from previous prime (28553809) and next prime (28553831).

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, 237889 + ... + 238008.

It is an arithmetic number, because the mean of its divisors is an integer number (3331286).

Almost surely, 2^28553820 is an apocalyptic number.

28553820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28553820 is an abundant number, since it is smaller than the sum of its proper divisors (51397044).

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

28553820 is a wasteful number, since it uses less digits than its factorization.

28553820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475909 (or 475907 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 33.

The square root of 28553820 is about 5343.5774533546. The cubic root of 28553820 is about 305.6478926567.

Adding to 28553820 its product of nonzero digits (19200), we get a triangular number (28573020 = T₇₅₅₉).

The spelling of 28553820 in words is "twenty-eight million, five hundred fifty-three thousand, eight hundred twenty".