4220640 has 96 divisors (see below), whose sum is σ = 14787360. Its totient is φ = 1124352.

The previous prime is 4220639. The next prime is 4220653. The reversal of 4220640 is 460224.

4220640 = T₁₄₅ + T₁₄₆ + ... + T₃₀₄.

4220640 is a `hidden beast` number, since 4 + 2 + 20 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a d-powerful number, because it can be written as 4⁷ + 2⁷ + 2¹¹ + 0 + 6⁵ + 4¹¹ + 0 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3832 + ... + 4808.

It is an arithmetic number, because the mean of its divisors is an integer number (154035).

Almost surely, 2^4220640 is an apocalyptic number.

4220640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 4220640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7393680).

4220640 is an abundant number, since it is smaller than the sum of its proper divisors (10566720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

4220640 is a wasteful number, since it uses less digits than its factorization.

4220640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001 (or 987 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 4220640 is about 2054.4196260745. The cubic root of 4220640 is about 161.6067278185.

Adding to 4220640 its reverse (460224), we get a palindrome (4680864).

The spelling of 4220640 in words is "four million, two hundred twenty thousand, six hundred forty".