28318920 has 64 divisors (see below), whose sum is σ = 97096320. Its totient is φ = 6472704.

The previous prime is 28318909. The next prime is 28318921. The reversal of 28318920 is 2981382.

It is a super-2 number, since 2×28318920² = 1603922459932800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28318921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16017 + ... + 17696.

It is an arithmetic number, because the mean of its divisors is an integer number (1517130).

Almost surely, 2^28318920 is an apocalyptic number.

28318920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28318920 is an abundant number, since it is smaller than the sum of its proper divisors (68777400).

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

28318920 is a wasteful number, since it uses less digits than its factorization.

28318920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33734 (or 33730 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 28318920 is about 5321.5524050788. The cubic root of 28318920 is about 304.8074391444.

The spelling of 28318920 in words is "twenty-eight million, three hundred eighteen thousand, nine hundred twenty".