778676640 has 144 divisors (see below), whose sum is σ = 2853379872. Its totient is φ = 177977856.

The previous prime is 778676617. The next prime is 778676659. The reversal of 778676640 is 46676877.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6967 + ... + 40073.

It is an arithmetic number, because the mean of its divisors is an integer number (19815138).

Almost surely, 2^778676640 is an apocalyptic number.

778676640 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 778676640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1426689936).

778676640 is an abundant number, since it is smaller than the sum of its proper divisors (2074703232).

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

778676640 is a wasteful number, since it uses less digits than its factorization.

778676640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33139 (or 33124 counting only the distinct ones).

The product of its (nonzero) digits is 2370816, while the sum is 51.

The square root of 778676640 is about 27904.7780854821. The cubic root of 778676640 is about 919.9955261282.

The spelling of 778676640 in words is "seven hundred seventy-eight million, six hundred seventy-six thousand, six hundred forty".