781828320 has 288 divisors, whose sum is σ = 3086421408. Its totient is φ = 164892672.

The previous prime is 781828301. The next prime is 781828337. The reversal of 781828320 is 23828187.

It is a super-2 number, since 2×781828320² = 1222511043908044800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 304482 + ... + 307038.

It is an arithmetic number, because the mean of its divisors is an integer number (10716741).

Almost surely, 2^781828320 is an apocalyptic number.

781828320 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 781828320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1543210704).

781828320 is an abundant number, since it is smaller than the sum of its proper divisors (2304593088).

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

781828320 is a wasteful number, since it uses less digits than its factorization.

781828320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2602 (or 2587 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 39.

The square root of 781828320 is about 27961.1931075911. The cubic root of 781828320 is about 921.2350771774.

The spelling of 781828320 in words is "seven hundred eighty-one million, eight hundred twenty-eight thousand, three hundred twenty".