3891280 has 40 divisors (see below), whose sum is σ = 9142272. Its totient is φ = 1540224.

The previous prime is 3891263. The next prime is 3891287. The reversal of 3891280 is 821983.

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

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3891287) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9969 + ... + 10351.

Almost surely, 2^3891280 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 3891280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4571136).

3891280 is an abundant number, since it is smaller than the sum of its proper divisors (5250992).

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

3891280 is a wasteful number, since it uses less digits than its factorization.

3891280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 3891280 is about 1972.6327585235. The cubic root of 3891280 is about 157.2886894943.

The spelling of 3891280 in words is "three million, eight hundred ninety-one thousand, two hundred eighty".