4208921 has 4 divisors (see below), whose sum is σ = 4217700. Its totient is φ = 4200144.

The previous prime is 4208903. The next prime is 4208923. The reversal of 4208921 is 1298024.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3667225 + 541696 = 1915^2 + 736^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4208921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4208923) 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, 3626 + ... + 4643.

It is an arithmetic number, because the mean of its divisors is an integer number (1054425).

Almost surely, 2^4208921 is an apocalyptic number.

It is an amenable number.

4208921 is a deficient number, since it is larger than the sum of its proper divisors (8779).

4208921 is an equidigital number, since it uses as much as digits as its factorization.

4208921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8778.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 4208921 is about 2051.5654998074. The cubic root of 4208921 is about 161.4570171279.

The spelling of 4208921 in words is "four million, two hundred eight thousand, nine hundred twenty-one".