221421436 has 6 divisors (see below), whose sum is σ = 387487520. Its totient is φ = 110710716.

The previous prime is 221421419. The next prime is 221421461. The reversal of 221421436 is 634124122.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 221421436.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 27677676 + ... + 27677683.

Almost surely, 2^221421436 is an apocalyptic number.

It is an amenable number.

221421436 is a deficient number, since it is larger than the sum of its proper divisors (166066084).

221421436 is a wasteful number, since it uses less digits than its factorization.

221421436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55355363 (or 55355361 counting only the distinct ones).

The product of its digits is 2304, while the sum is 25.

The square root of 221421436 is about 14880.2364228530. The cubic root of 221421436 is about 604.9784260230.

Adding to 221421436 its reverse (634124122), we get a palindrome (855545558).

The spelling of 221421436 in words is "two hundred twenty-one million, four hundred twenty-one thousand, four hundred thirty-six".