28491288 has 32 divisors (see below), whose sum is σ = 81404160. Its totient is φ = 8140320.

The previous prime is 28491283. The next prime is 28491289. The reversal of 28491288 is 88219482.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28491283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84628 + ... + 84963.

It is an arithmetic number, because the mean of its divisors is an integer number (2543880).

Almost surely, 2^28491288 is an apocalyptic number.

28491288 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28491288 is an abundant number, since it is smaller than the sum of its proper divisors (52912872).

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

28491288 is a wasteful number, since it uses less digits than its factorization.

28491288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169607 (or 169603 counting only the distinct ones).

The product of its digits is 73728, while the sum is 42.

The square root of 28491288 is about 5337.7231100910. The cubic root of 28491288 is about 305.4246097106.

The spelling of 28491288 in words is "twenty-eight million, four hundred ninety-one thousand, two hundred eighty-eight".