28380555 has 72 divisors (see below), whose sum is σ = 58438224. Its totient is φ = 12700800.

The previous prime is 28380553. The next prime is 28380557. The reversal of 28380555 is 55508382.

28380555 is a `hidden beast` number, since 28 + 3 + 80 + 555 = 666.

It is an interprime number because it is at equal distance from previous prime (28380553) and next prime (28380557).

It is not a de Polignac number, because 28380555 - 2¹ = 28380553 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28380553) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 134400 + ... + 134610.

It is an arithmetic number, because the mean of its divisors is an integer number (811642).

Almost surely, 2^28380555 is an apocalyptic number.

28380555 is an abundant number, since it is smaller than the sum of its proper divisors (30057669).

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

28380555 is a wasteful number, since it uses less digits than its factorization.

28380555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 287 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 36.

The square root of 28380555 is about 5327.3403307842. The cubic root of 28380555 is about 305.0284126536.

The spelling of 28380555 in words is "twenty-eight million, three hundred eighty thousand, five hundred fifty-five".