781385814 has 144 divisors (see below), whose sum is σ = 1959939072. Its totient is φ = 224532000.

The previous prime is 781385767. The next prime is 781385833. The reversal of 781385814 is 418583187.

It is a happy number.

It is a super-2 number, since 2×781385814² = 1221127580640885192, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 781385814.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4793697 + ... + 4793859.

It is an arithmetic number, because the mean of its divisors is an integer number (13610688).

Almost surely, 2^781385814 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781385814, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (979969536).

781385814 is an abundant number, since it is smaller than the sum of its proper divisors (1178553258).

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

781385814 is a wasteful number, since it uses less digits than its factorization.

781385814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 281 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The square root of 781385814 is about 27953.2791278590. The cubic root of 781385814 is about 921.0612414935.

The spelling of 781385814 in words is "seven hundred eighty-one million, three hundred eighty-five thousand, eight hundred fourteen".