4021866 has 32 divisors (see below), whose sum is σ = 9072000. Its totient is φ = 1320480.

The previous prime is 4021777. The next prime is 4021867. The reversal of 4021866 is 6681204.

It is a super-2 number, since 2×4021866² = 32350812243912, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (4021867) 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, 3310 + ... + 4358.

It is an arithmetic number, because the mean of its divisors is an integer number (283500).

Almost surely, 2^4021866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 4021866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4536000).

4021866 is an abundant number, since it is smaller than the sum of its proper divisors (5050134).

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

4021866 is a wasteful number, since it uses less digits than its factorization.

4021866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131 (or 1125 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 4021866 is about 2005.4590496941. The cubic root of 4021866 is about 159.0288306566.

The spelling of 4021866 in words is "four million, twenty-one thousand, eight hundred sixty-six".