8649821 has 8 divisors (see below), whose sum is σ = 9263160. Its totient is φ = 8048128.

The previous prime is 8649803. The next prime is 8649847. The reversal of 8649821 is 1289468.

It can be written as a sum of positive squares in 4 ways, for example, as 1413721 + 7236100 = 1189^2 + 2690^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8649821 - 2⁶ = 8649757 is a prime.

It is a super-3 number, since 3×8649821³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8649871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1346 + ... + 4371.

It is an arithmetic number, because the mean of its divisors is an integer number (1157895).

Almost surely, 2^8649821 is an apocalyptic number.

It is an amenable number.

8649821 is a deficient number, since it is larger than the sum of its proper divisors (613339).

8649821 is a wasteful number, since it uses less digits than its factorization.

8649821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5823.

The product of its digits is 27648, while the sum is 38.

The square root of 8649821 is about 2941.0578029002. The cubic root of 8649821 is about 205.2748326508.

The spelling of 8649821 in words is "eight million, six hundred forty-nine thousand, eight hundred twenty-one".