28129556 has 24 divisors (see below), whose sum is σ = 60587520. Its totient is φ = 11128032.

The previous prime is 28129553. The next prime is 28129559. The reversal of 28129556 is 65592182.

It is an interprime number because it is at equal distance from previous prime (28129553) and next prime (28129559).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28129553) 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, 38276 + ... + 39003.

It is an arithmetic number, because the mean of its divisors is an integer number (2524480).

Almost surely, 2^28129556 is an apocalyptic number.

28129556 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

28129556 is an abundant number, since it is smaller than the sum of its proper divisors (32457964).

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

28129556 is a wasteful number, since it uses less digits than its factorization.

28129556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77303 (or 77301 counting only the distinct ones).

The product of its digits is 43200, while the sum is 38.

The square root of 28129556 is about 5303.7303853043. The cubic root of 28129556 is about 304.1265199364.

The spelling of 28129556 in words is "twenty-eight million, one hundred twenty-nine thousand, five hundred fifty-six".