28315440 has 80 divisors (see below), whose sum is σ = 97538400. Its totient is φ = 7550208.

The previous prime is 28315433. The next prime is 28315481. The reversal of 28315440 is 4451382.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4395 + ... + 8714.

It is an arithmetic number, because the mean of its divisors is an integer number (1219230).

Almost surely, 2^28315440 is an apocalyptic number.

28315440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28315440 is an abundant number, since it is smaller than the sum of its proper divisors (69222960).

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

28315440 is a wasteful number, since it uses less digits than its factorization.

28315440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13131 (or 13119 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 28315440 is about 5321.2254227762. The cubic root of 28315440 is about 304.7949531063.

The spelling of 28315440 in words is "twenty-eight million, three hundred fifteen thousand, four hundred forty".