4021986 has 16 divisors (see below), whose sum is σ = 8082144. Its totient is φ = 1334304.

The previous prime is 4021973. The next prime is 4022003. The reversal of 4021986 is 6891204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115 + ... + 2838.

It is an arithmetic number, because the mean of its divisors is an integer number (505134).

Almost surely, 2^4021986 is an apocalyptic number.

4021986 is an abundant number, since it is smaller than the sum of its proper divisors (4060158).

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

4021986 is a wasteful number, since it uses less digits than its factorization.

4021986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3185.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 4021986 is about 2005.4889678081. The cubic root of 4021986 is about 159.0304122832.

It can be divided in two parts, 402198 and 6, that added together give a palindrome (402204).

The spelling of 4021986 in words is "four million, twenty-one thousand, nine hundred eighty-six".