4208549021 has 4 divisors (see below), whose sum is σ = 4229912412. Its totient is φ = 4187185632.

The previous prime is 4208548999. The next prime is 4208549041. The reversal of 4208549021 is 1209458024.

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 4051322500 + 157226521 = 63650^2 + 12539^2 .

It is a cyclic number.

It is not a de Polignac number, because 4208549021 - 2¹⁰ = 4208547997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4208549041) 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, 10681400 + ... + 10681793.

It is an arithmetic number, because the mean of its divisors is an integer number (1057478103).

Almost surely, 2^4208549021 is an apocalyptic number.

It is an amenable number.

4208549021 is a deficient number, since it is larger than the sum of its proper divisors (21363391).

4208549021 is a wasteful number, since it uses less digits than its factorization.

4208549021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21363390.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 4208549021 is about 64873.3305835302. The cubic root of 4208549021 is about 1614.5226053358.

The spelling of 4208549021 in words is "four billion, two hundred eight million, five hundred forty-nine thousand, twenty-one".