75440 has 40 divisors (see below), whose sum is σ = 187488. Its totient is φ = 28160.

The previous prime is 75437. The next prime is 75479. The reversal of 75440 is 4457.

75440 = T₃₉ + T₄₀ + ... + T₇₉.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1820 + ... + 1860.

2⁷⁵⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 75440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93744).

75440 is an abundant number, since it is smaller than the sum of its proper divisors (112048).

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

75440 is a wasteful number, since it uses less digits than its factorization.

75440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 20.

The square root of 75440 is about 274.6634304016. The cubic root of 75440 is about 42.2539414877.

Adding to 75440 its reverse (4457), we get a palindrome (79897).

It can be divided in two parts, 75 and 440, that added together give a palindrome (515).

The spelling of 75440 in words is "seventy-five thousand, four hundred forty".