28155380 has 24 divisors (see below), whose sum is σ = 64501920. Its totient is φ = 10238240.

The previous prime is 28155377. The next prime is 28155389. The reversal of 28155380 is 8355182.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28155389) 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, 63770 + ... + 64209.

It is an arithmetic number, because the mean of its divisors is an integer number (2687580).

Almost surely, 2^28155380 is an apocalyptic number.

28155380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28155380 is an abundant number, since it is smaller than the sum of its proper divisors (36346540).

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

28155380 is a wasteful number, since it uses less digits than its factorization.

28155380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127999 (or 127997 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 28155380 is about 5306.1643397091. The cubic root of 28155380 is about 304.2195580339.

The spelling of 28155380 in words is "twenty-eight million, one hundred fifty-five thousand, three hundred eighty".