778421412 has 108 divisors (see below), whose sum is σ = 2103142860. Its totient is φ = 242694144.

The previous prime is 778421401. The next prime is 778421419. The reversal of 778421412 is 214124877.

It can be written as a sum of positive squares in 2 ways, for example, as 199826496 + 578594916 = 14136^2 + 24054^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (778421419) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1156308 + ... + 1156980.

It is an arithmetic number, because the mean of its divisors is an integer number (19473545).

Almost surely, 2^778421412 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 778421412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1051571430).

778421412 is an abundant number, since it is smaller than the sum of its proper divisors (1324721448).

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

778421412 is a wasteful number, since it uses less digits than its factorization.

778421412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810 (or 786 counting only the distinct ones).

The product of its digits is 25088, while the sum is 36.

The square root of 778421412 is about 27900.2045153795. The cubic root of 778421412 is about 919.8949990436.

The spelling of 778421412 in words is "seven hundred seventy-eight million, four hundred twenty-one thousand, four hundred twelve".