778315648 has 64 divisors (see below), whose sum is σ = 1696353840. Its totient is φ = 352768000.

The previous prime is 778315621. The next prime is 778315649. The reversal of 778315648 is 846513877.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×778315648³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778315649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 733038 + ... + 734098.

Almost surely, 2^778315648 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 778315648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (848176920).

778315648 is an abundant number, since it is smaller than the sum of its proper divisors (918038192).

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

778315648 is a wasteful number, since it uses less digits than its factorization.

778315648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1607 (or 1595 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 49.

The square root of 778315648 is about 27898.3090527007. The cubic root of 778315648 is about 919.8533351583.

The spelling of 778315648 in words is "seven hundred seventy-eight million, three hundred fifteen thousand, six hundred forty-eight".