221681241 has 24 divisors (see below), whose sum is σ = 343833984. Its totient is φ = 137128320.

The previous prime is 221681237. The next prime is 221681321. The reversal of 221681241 is 142186122.

It is not a de Polignac number, because 221681241 - 2² = 221681237 is a prime.

It is a super-2 number, since 2×221681241² = 98285145222600162, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221691241) 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, 660 + ... + 21066.

It is an arithmetic number, because the mean of its divisors is an integer number (14326416).

Almost surely, 2^221681241 is an apocalyptic number.

It is an amenable number.

221681241 is a deficient number, since it is larger than the sum of its proper divisors (122152743).

221681241 is a wasteful number, since it uses less digits than its factorization.

221681241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20501 (or 20498 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 221681241 is about 14888.9637315698. The cubic root of 221681241 is about 605.2149508276.

It can be divided in two parts, 22168 and 1241, that added together give a square (23409 = 153²).

The spelling of 221681241 in words is "two hundred twenty-one million, six hundred eighty-one thousand, two hundred forty-one".