28135440 has 120 divisors (see below), whose sum is σ = 98654400. Its totient is φ = 7172352.

The previous prime is 28135439. The next prime is 28135483. The reversal of 28135440 is 4453182.

28135440 = 1095² + 1096² + ... + 1117².

It is a tau number, because it is divible by the number of its divisors (120).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15711 + ... + 17409.

It is an arithmetic number, because the mean of its divisors is an integer number (822120).

Almost surely, 2^28135440 is an apocalyptic number.

28135440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28135440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49327200).

28135440 is an abundant number, since it is smaller than the sum of its proper divisors (70518960).

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

28135440 is a wasteful number, since it uses less digits than its factorization.

28135440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1741 (or 1732 counting only the distinct ones).

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

The square root of 28135440 is about 5304.2850602131. The cubic root of 28135440 is about 304.1477236801.

It can be divided in two parts, 281 and 35440, that added together give a square (35721 = 189²).

The spelling of 28135440 in words is "twenty-eight million, one hundred thirty-five thousand, four hundred forty".