221481481 has 4 divisors (see below), whose sum is σ = 238518532. Its totient is φ = 204444432.

The previous prime is 221481473. The next prime is 221481493. The reversal of 221481481 is 184184122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30074256 + 191407225 = 5484^2 + 13835^2 .

It is a cyclic number.

It is not a de Polignac number, because 221481481 - 2³ = 221481473 is a prime.

It is a super-2 number, since 2×221481481² = 98108092851906722, which contains 22 as substring.

It is a Duffinian number.

221481481 is a modest number, since divided by 481481 gives 221 as remainder.

It is not an unprimeable number, because it can be changed into a prime (221481451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8518506 + ... + 8518531.

It is an arithmetic number, because the mean of its divisors is an integer number (59629633).

Almost surely, 2^221481481 is an apocalyptic number.

It is an amenable number.

221481481 is a deficient number, since it is larger than the sum of its proper divisors (17037051).

221481481 is a wasteful number, since it uses less digits than its factorization.

221481481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17037050.

The product of its digits is 4096, while the sum is 31.

The square root of 221481481 is about 14882.2538951598. The cubic root of 221481481 is about 605.0331070378.

The spelling of 221481481 in words is "two hundred twenty-one million, four hundred eighty-one thousand, four hundred eighty-one".