28961388 has 30 divisors (see below), whose sum is σ = 75711636. Its totient is φ = 9653688.

The previous prime is 28961381. The next prime is 28961399. The reversal of 28961388 is 88316982.

28961388 is a `hidden beast` number, since 28 + 9 + 613 + 8 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (28961381) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 44370 + ... + 45017.

Almost surely, 2^28961388 is an apocalyptic number.

It is an amenable number.

28961388 is an abundant number, since it is smaller than the sum of its proper divisors (46750248).

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

28961388 is a wasteful number, since it uses less digits than its factorization.

28961388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89403 (or 89392 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 28961388 is about 5381.5785788187. The cubic root of 28961388 is about 307.0952676428.

The spelling of 28961388 in words is "twenty-eight million, nine hundred sixty-one thousand, three hundred eighty-eight".