221137844 has 6 divisors (see below), whose sum is σ = 386991234. Its totient is φ = 110568920.

The previous prime is 221137843. The next prime is 221137877. The reversal of 221137844 is 448731122.

It can be written as a sum of positive squares in only one way, i.e., 183927844 + 37210000 = 13562^2 + 6100^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 221137844.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221137843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27642227 + ... + 27642234.

It is an arithmetic number, because the mean of its divisors is an integer number (64498539).

Almost surely, 2^221137844 is an apocalyptic number.

It is an amenable number.

221137844 is a deficient number, since it is larger than the sum of its proper divisors (165853390).

221137844 is a wasteful number, since it uses less digits than its factorization.

221137844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55284465 (or 55284463 counting only the distinct ones).

The product of its digits is 10752, while the sum is 32.

The square root of 221137844 is about 14870.7042200428. The cubic root of 221137844 is about 604.7200343883.

Adding to 221137844 its reverse (448731122), we get a palindrome (669868966).

The spelling of 221137844 in words is "two hundred twenty-one million, one hundred thirty-seven thousand, eight hundred forty-four".