4021664 has 24 divisors (see below), whose sum is σ = 7997220. Its totient is φ = 1990656.

The previous prime is 4021663. The next prime is 4021727. The reversal of 4021664 is 4661204.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 3763600 + 258064 = 1940^2 + 508^2 .

It is not an unprimeable number, because it can be changed into a prime (4021663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2912 + ... + 4064.

Almost surely, 2^4021664 is an apocalyptic number.

It is an amenable number.

4021664 is a deficient number, since it is larger than the sum of its proper divisors (3975556).

4021664 is a wasteful number, since it uses less digits than its factorization.

4021664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1272 (or 1264 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 4021664 is about 2005.4086865275. The cubic root of 4021664 is about 159.0261681809.

Adding to 4021664 its reverse (4661204), we get a palindrome (8682868).

The spelling of 4021664 in words is "four million, twenty-one thousand, six hundred sixty-four".