4021491 has 4 divisors (see below), whose sum is σ = 5361992. Its totient is φ = 2680992.

The previous prime is 4021477. The next prime is 4021513. The reversal of 4021491 is 1941204.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 4021491 - 2⁶ = 4021427 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4021411) 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, 670246 + ... + 670251.

It is an arithmetic number, because the mean of its divisors is an integer number (1340498).

Almost surely, 2^4021491 is an apocalyptic number.

4021491 is a deficient number, since it is larger than the sum of its proper divisors (1340501).

4021491 is a wasteful number, since it uses less digits than its factorization.

4021491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1340500.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 4021491 is about 2005.3655527110. The cubic root of 4021491 is about 159.0238878709.

Adding to 4021491 its reverse (1941204), we get a palindrome (5962695).

The spelling of 4021491 in words is "four million, twenty-one thousand, four hundred ninety-one".