778975699216 has 135 divisors (see below), whose sum is σ = 1797536960037. Its totient is φ = 326631127680.

The previous prime is 778975699141. The next prime is 778975699237. The reversal of 778975699216 is 612996579877.

It is a happy number.

The square root of 778975699216 is 882596.

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., 115233091600 + 663742607616 = 339460^2 + 814704^2 .

It is a super-2 number, since 2×778975699216² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 504844141 + ... + 504845683.

Almost surely, 2^778975699216 is an apocalyptic number.

778975699216 is the 882596-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778975699216

778975699216 is an abundant number, since it is smaller than the sum of its proper divisors (1018561260821).

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

778975699216 is a wasteful number, since it uses less digits than its factorization.

778975699216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3142 (or 1569 counting only the distinct ones).

The product of its digits is 720135360, while the sum is 76.

The spelling of 778975699216 in words is "seven hundred seventy-eight billion, nine hundred seventy-five million, six hundred ninety-nine thousand, two hundred sixteen".