778947840 has 360 divisors, whose sum is σ = 3045053088. Its totient is φ = 188559360.

The previous prime is 778947809. The next prime is 778947853. The reversal of 778947840 is 48749877.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1140139 + ... + 1140821.

Almost surely, 2^778947840 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 778947840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1522526544).

778947840 is an abundant number, since it is smaller than the sum of its proper divisors (2266105248).

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

778947840 is a wasteful number, since it uses less digits than its factorization.

778947840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727 (or 704 counting only the distinct ones).

The product of its (nonzero) digits is 3161088, while the sum is 54.

The square root of 778947840 is about 27909.6370452932. The cubic root of 778947840 is about 920.1023200628.

The spelling of 778947840 in words is "seven hundred seventy-eight million, nine hundred forty-seven thousand, eight hundred forty".