222222777778 has 8 divisors (see below), whose sum is σ = 333336666672. Its totient is φ = 111110555556.

The previous prime is 222222777767. The next prime is 222222777913. The reversal of 222222777778 is 877777222222.

222222777778 is a nontrivial binomial coefficient, being equal to C(666668, 2).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 666667.

It is an arithmetic number, because the mean of its divisors is an integer number (41667083334).

Almost surely, 2^222222777778 is an apocalyptic number.

222222777778 is the 666667-th triangular number and also the 333334-th hexagonal number.

222222777778 is the 222223-rd centered nonagonal number.

222222777778 is a deficient number, since it is larger than the sum of its proper divisors (111113888894).

222222777778 is a wasteful number, since it uses less digits than its factorization.

222222777778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833336.

The product of its digits is 8605184, while the sum is 55.

It can be divided in two parts, 222222 and 777778, that added together give a 6-th power (1000000 = 10⁶).

The spelling of 222222777778 in words is "two hundred twenty-two billion, two hundred twenty-two million, seven hundred seventy-seven thousand, seven hundred seventy-eight".