32781440 has 128 divisors (see below), whose sum is σ = 87246720. Its totient is φ = 11714560.

The previous prime is 32781439. The next prime is 32781449. The reversal of 32781440 is 4418723.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (32781449) 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, 250175 + ... + 250305.

It is an arithmetic number, because the mean of its divisors is an integer number (681615).

Almost surely, 2^32781440 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 32781440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43623360).

32781440 is an abundant number, since it is smaller than the sum of its proper divisors (54465280).

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

32781440 is a wasteful number, since it uses less digits than its factorization.

32781440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 32781440 is about 5725.5078377381. The cubic root of 32781440 is about 320.0437440199.

The spelling of 32781440 in words is "thirty-two million, seven hundred eighty-one thousand, four hundred forty".