778212 has 18 divisors (see below), whose sum is σ = 1967238. Its totient is φ = 259392.

The previous prime is 778201. The next prime is 778213. The reversal of 778212 is 212877.

It can be written as a sum of positive squares in only one way, i.e., 553536 + 224676 = 744^2 + 474^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×778212² = 1211227833888, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 778212.

It is not an unprimeable number, because it can be changed into a prime (778213) by changing a digit.

778212 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10773 + ... + 10844.

It is an arithmetic number, because the mean of its divisors is an integer number (109291).

2⁷⁷⁸²¹² is an apocalyptic number.

It is an amenable number.

778212 is an abundant number, since it is smaller than the sum of its proper divisors (1189026).

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

778212 is a wasteful number, since it uses less digits than its factorization.

778212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21627 (or 21622 counting only the distinct ones).

The product of its digits is 1568, while the sum is 27.

The square root of 778212 is about 882.1632501981. The cubic root of 778212 is about 91.9812501172.

It can be divided in two parts, 778 and 212, that added together give a triangular number (990 = T₄₄).

The spelling of 778212 in words is "seven hundred seventy-eight thousand, two hundred twelve".