8723621 has 4 divisors (see below), whose sum is σ = 8743500. Its totient is φ = 8703744.

The previous prime is 8723609. The next prime is 8723639. The reversal of 8723621 is 1263278.

It is a happy number.

8723621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 1890625 + 6832996 = 1375^2 + 2614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8723621 is a prime.

It is a super-2 number, since 2×8723621² = 152203126703282, which contains 22 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 (8723321) 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, 9266 + ... + 10163.

It is an arithmetic number, because the mean of its divisors is an integer number (2185875).

Almost surely, 2^8723621 is an apocalyptic number.

It is an amenable number.

8723621 is a deficient number, since it is larger than the sum of its proper divisors (19879).

8723621 is a wasteful number, since it uses less digits than its factorization.

8723621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19878.

The product of its digits is 4032, while the sum is 29.

The square root of 8723621 is about 2953.5776610748. The cubic root of 8723621 is about 205.8569796230.

Adding to 8723621 its reverse (1263278), we get a palindrome (9986899).

The spelling of 8723621 in words is "eight million, seven hundred twenty-three thousand, six hundred twenty-one".