221739849 has 40 divisors (see below), whose sum is σ = 354195072. Its totient is φ = 137903040.

The previous prime is 221739811. The next prime is 221739871. The reversal of 221739849 is 948937122.

221739849 is a `hidden beast` number, since 2 + 217 + 398 + 49 = 666.

It is not a de Polignac number, because 221739849 - 2⁹ = 221739337 is a prime.

It is a super-3 number, since 3×221739849³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221739149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 74932 + ... + 77834.

Almost surely, 2^221739849 is an apocalyptic number.

It is an amenable number.

221739849 is a deficient number, since it is larger than the sum of its proper divisors (132455223).

221739849 is a wasteful number, since it uses less digits than its factorization.

221739849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2979 (or 2970 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 221739849 is about 14890.9317707120. The cubic root of 221739849 is about 605.2682816256.

The spelling of 221739849 in words is "two hundred twenty-one million, seven hundred thirty-nine thousand, eight hundred forty-nine".