221142818 has 16 divisors (see below), whose sum is σ = 363973176. Its totient is φ = 100139520.

The previous prime is 221142791. The next prime is 221142829. The reversal of 221142818 is 818241122.

It can be written as a sum of positive squares in 4 ways, for example, as 123587689 + 97555129 = 11117^2 + 9877^2 .

It is a super-2 number, since 2×221142818² = 97808291905962248, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78863 + ... + 81618.

Almost surely, 2^221142818 is an apocalyptic number.

221142818 is a deficient number, since it is larger than the sum of its proper divisors (142830358).

221142818 is a wasteful number, since it uses less digits than its factorization.

221142818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160549.

The product of its digits is 2048, while the sum is 29.

The square root of 221142818 is about 14870.8714606778. The cubic root of 221142818 is about 604.7245682947.

The spelling of 221142818 in words is "two hundred twenty-one million, one hundred forty-two thousand, eight hundred eighteen".