221024421 has 12 divisors (see below), whose sum is σ = 327886572. Its totient is φ = 143366976.

The previous prime is 221024413. The next prime is 221024431. The reversal of 221024421 is 124420122.

221024421 is a `hidden beast` number, since 221 + 0 + 2 + 442 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 101909025 + 119115396 = 10095^2 + 10914^2 .

It is not a de Polignac number, because 221024421 - 2³ = 221024413 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221024394 and 221024403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221024431) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 331536 + ... + 332201.

It is an arithmetic number, because the mean of its divisors is an integer number (27323881).

Almost surely, 2^221024421 is an apocalyptic number.

It is an amenable number.

221024421 is a deficient number, since it is larger than the sum of its proper divisors (106862151).

221024421 is a wasteful number, since it uses less digits than its factorization.

221024421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663780 (or 663777 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 221024421 is about 14866.8900917441. The cubic root of 221024421 is about 604.6166284626.

Adding to 221024421 its reverse (124420122), we get a palindrome (345444543).

It can be divided in two parts, 221024 and 421, that added together give a triangular number (221445 = T₆₆₅).

The spelling of 221024421 in words is "two hundred twenty-one million, twenty-four thousand, four hundred twenty-one".