781025280 has 256 divisors, whose sum is σ = 2868860160. Its totient is φ = 177733632.

The previous prime is 781025261. The next prime is 781025299. The reversal of 781025280 is 82520187.

It is an interprime number because it is at equal distance from previous prime (781025261) and next prime (781025299).

It is a tau number, because it is divible by the number of its divisors (256).

It is a super-2 number, since 2×781025280² = 1220000975998156800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3440527 + ... + 3440753.

It is an arithmetic number, because the mean of its divisors is an integer number (11206485).

Almost surely, 2^781025280 is an apocalyptic number.

781025280 is a gapful number since it is divisible by the number (70) 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 781025280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1434430080).

781025280 is an abundant number, since it is smaller than the sum of its proper divisors (2087834880).

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

781025280 is an equidigital number, since it uses as much as digits as its factorization.

781025280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 781025280 is about 27946.8295160650. The cubic root of 781025280 is about 920.9195594656.

The spelling of 781025280 in words is "seven hundred eighty-one million, twenty-five thousand, two hundred eighty".