2221551818 has 8 divisors (see below), whose sum is σ = 3358566912. Its totient is φ = 1102029516.

The previous prime is 2221551809. The next prime is 2221551881. The reversal of 2221551818 is 8181551222.

It is a happy number.

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

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, 4372880 + ... + 4373387.

It is an arithmetic number, because the mean of its divisors is an integer number (419820864).

Almost surely, 2^2221551818 is an apocalyptic number.

2221551818 is a deficient number, since it is larger than the sum of its proper divisors (1137015094).

2221551818 is a wasteful number, since it uses less digits than its factorization.

2221551818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8746396.

The product of its digits is 12800, while the sum is 35.

The square root of 2221551818 is about 47133.3408321540. The cubic root of 2221551818 is about 1304.8246400013.

The spelling of 2221551818 in words is "two billion, two hundred twenty-one million, five hundred fifty-one thousand, eight hundred eighteen".