780402816 has 256 divisors, whose sum is σ = 2511648000. Its totient is φ = 237551616.

The previous prime is 780402809. The next prime is 780402823. The reversal of 780402816 is 618204087.

It is an interprime number because it is at equal distance from previous prime (780402809) and next prime (780402823).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2173645 + ... + 2174003.

It is an arithmetic number, because the mean of its divisors is an integer number (9811125).

Almost surely, 2^780402816 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 780402816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1255824000).

780402816 is an abundant number, since it is smaller than the sum of its proper divisors (1731245184).

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

780402816 is a wasteful number, since it uses less digits than its factorization.

780402816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 780402816 is about 27935.6907199375. The cubic root of 780402816 is about 920.6748419803.

The spelling of 780402816 in words is "seven hundred eighty million, four hundred two thousand, eight hundred sixteen".