781280 has 48 divisors (see below), whose sum is σ = 1950480. Its totient is φ = 294912.

The previous prime is 781271. The next prime is 781283. The reversal of 781280 is 82187.

It is a super-2 number, since 2×781280² = 1220796876800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781283) 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, 2912 + ... + 3168.

It is an arithmetic number, because the mean of its divisors is an integer number (40635).

2⁷⁸¹²⁸⁰ 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 781280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (975240).

781280 is an abundant number, since it is smaller than the sum of its proper divisors (1169200).

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

781280 is a wasteful number, since it uses less digits than its factorization.

781280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 283 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 781280 is about 883.9004468830. The cubic root of 781280 is about 92.1019663410.

The spelling of 781280 in words is "seven hundred eighty-one thousand, two hundred eighty".