1778222 has 32 divisors (see below), whose sum is σ = 3041280. Its totient is φ = 776160.

The previous prime is 1778221. The next prime is 1778239. The reversal of 1778222 is 2228771.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1778221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41333 + ... + 41375.

It is an arithmetic number, because the mean of its divisors is an integer number (95040).

2^1778222 is an apocalyptic number.

It is a pronic number, being equal to 1333×1334.

1778222 is a deficient number, since it is larger than the sum of its proper divisors (1263058).

1778222 is a wasteful number, since it uses less digits than its factorization.

1778222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128.

The product of its digits is 3136, while the sum is 29.

The square root of 1778222 is about 1333.4999062617. The cubic root of 1778222 is about 121.1514620820.

It can be divided in two parts, 1778 and 222, that multiplied together give a triangular number (394716 = T₈₈₈).

The spelling of 1778222 in words is "one million, seven hundred seventy-eight thousand, two hundred twenty-two".