221855444 has 24 divisors (see below), whose sum is σ = 392041608. Its totient is φ = 109848960.

The previous prime is 221855407. The next prime is 221855483. The reversal of 221855444 is 444558122.

It can be written as a sum of positive squares in 4 ways, for example, as 1926544 + 219928900 = 1388^2 + 14830^2 .

It is a congruent number.

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, 339422 + ... + 340074.

It is an arithmetic number, because the mean of its divisors is an integer number (16335067).

Almost surely, 2^221855444 is an apocalyptic number.

It is an amenable number.

221855444 is a deficient number, since it is larger than the sum of its proper divisors (170186164).

221855444 is a wasteful number, since it uses less digits than its factorization.

221855444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1355 (or 1353 counting only the distinct ones).

The product of its digits is 51200, while the sum is 35.

The square root of 221855444 is about 14894.8126540752. The cubic root of 221855444 is about 605.3734406409.

The spelling of 221855444 in words is "two hundred twenty-one million, eight hundred fifty-five thousand, four hundred forty-four".