221955545 has 24 divisors (see below), whose sum is σ = 310485384. Its totient is φ = 151877376.

The previous prime is 221955541. The next prime is 221955571. The reversal of 221955545 is 545559122.

It can be written as a sum of positive squares in 4 ways, for example, as 116359369 + 105596176 = 10787^2 + 10276^2 .

It is not a de Polignac number, because 221955545 - 2² = 221955541 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221955499 and 221955508.

It is not an unprimeable number, because it can be changed into a prime (221955541) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 214349 + ... + 215381.

It is an arithmetic number, because the mean of its divisors is an integer number (12936891).

Almost surely, 2^221955545 is an apocalyptic number.

It is an amenable number.

221955545 is a deficient number, since it is larger than the sum of its proper divisors (88529839).

221955545 is a wasteful number, since it uses less digits than its factorization.

221955545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1929 (or 1922 counting only the distinct ones).

The product of its digits is 90000, while the sum is 38.

The square root of 221955545 is about 14898.1725389391. The cubic root of 221955545 is about 605.4644749559.

The spelling of 221955545 in words is "two hundred twenty-one million, nine hundred fifty-five thousand, five hundred forty-five".