4221645 has 16 divisors (see below), whose sum is σ = 6780672. Its totient is φ = 2242880.

The previous prime is 4221643. The next prime is 4221649. The reversal of 4221645 is 5461224.

It is not a de Polignac number, because 4221645 - 2¹ = 4221643 is a prime.

It is a super-3 number, since 3×4221645³ (a number of 21 digits) contains 333 as substring.

It is an Ulam number.

It is a Curzon number.

4221645 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4221641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6139 + ... + 6791.

It is an arithmetic number, because the mean of its divisors is an integer number (423792).

Almost surely, 2^4221645 is an apocalyptic number.

It is an amenable number.

4221645 is a deficient number, since it is larger than the sum of its proper divisors (2559027).

4221645 is a wasteful number, since it uses less digits than its factorization.

4221645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092.

The product of its digits is 1920, while the sum is 24.

The square root of 4221645 is about 2054.6642061417. The cubic root of 4221645 is about 161.6195538253.

Adding to 4221645 its reverse (5461224), we get a palindrome (9682869).

The spelling of 4221645 in words is "four million, two hundred twenty-one thousand, six hundred forty-five".