778633216 has 51 divisors (see below), whose sum is σ = 1571672361. Its totient is φ = 385744896.

The previous prime is 778633211. The next prime is 778633223. The reversal of 778633216 is 612336877.

The square root of 778633216 is 27904.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 542703616 + 235929600 = 23296^2 + 15360^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (778633211) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7143370 + ... + 7143478.

Almost surely, 2^778633216 is an apocalyptic number.

778633216 is the 27904-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778633216

778633216 is an abundant number, since it is smaller than the sum of its proper divisors (793039145).

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

778633216 is an frugal number, since it uses more digits than its factorization.

778633216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 111 counting only the distinct ones).

The product of its digits is 254016, while the sum is 43.

The cubic root of 778633216 is about 919.9784241947.

Multiplying 778633216 by its product of digits (254016), we get a square (197785294995456 = 14063616²).

The spelling of 778633216 in words is "seven hundred seventy-eight million, six hundred thirty-three thousand, two hundred sixteen".