222778421 has 4 divisors (see below), whose sum is σ = 235883052. Its totient is φ = 209673792.

The previous prime is 222778411. The next prime is 222778429. The reversal of 222778421 is 124877222.

222778421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 156600196 + 66178225 = 12514^2 + 8135^2 .

It is a cyclic number.

It is not a de Polignac number, because 222778421 - 2²⁶ = 155669557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222778429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6552290 + ... + 6552323.

It is an arithmetic number, because the mean of its divisors is an integer number (58970763).

Almost surely, 2^222778421 is an apocalyptic number.

It is an amenable number.

222778421 is a deficient number, since it is larger than the sum of its proper divisors (13104631).

222778421 is a wasteful number, since it uses less digits than its factorization.

222778421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13104630.

The product of its digits is 25088, while the sum is 35.

The square root of 222778421 is about 14925.7636655549. The cubic root of 222778421 is about 606.2117833847.

The spelling of 222778421 in words is "two hundred twenty-two million, seven hundred seventy-eight thousand, four hundred twenty-one".