778453604640 has 144 divisors (see below), whose sum is σ = 2662212728448. Its totient is φ = 207139097088.

The previous prime is 778453604611. The next prime is 778453604647. The reversal of 778453604640 is 46406354877.

778453604640 is a `hidden beast` number, since 7 + 78 + 4 + 53 + 60 + 464 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-3 number, since 3×778453604640³ (a number of 37 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (778453604647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82927 + ... + 1250513.

It is an arithmetic number, because the mean of its divisors is an integer number (18487588392).

Almost surely, 2^778453604640 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 778453604640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1331106364224).

778453604640 is an abundant number, since it is smaller than the sum of its proper divisors (1883759123808).

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

778453604640 is a wasteful number, since it uses less digits than its factorization.

778453604640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1168071 (or 1168060 counting only the distinct ones).

The product of its (nonzero) digits is 13547520, while the sum is 54.

The spelling of 778453604640 in words is "seven hundred seventy-eight billion, four hundred fifty-three million, six hundred four thousand, six hundred forty".