8617821 has 4 divisors (see below), whose sum is σ = 11490432. Its totient is φ = 5745212.

The previous prime is 8617799. The next prime is 8617823. The reversal of 8617821 is 1287168.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8617821 - 2¹⁵ = 8585053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8617823) 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, 1436301 + ... + 1436306.

It is an arithmetic number, because the mean of its divisors is an integer number (2872608).

Almost surely, 2^8617821 is an apocalyptic number.

It is an amenable number.

8617821 is a deficient number, since it is larger than the sum of its proper divisors (2872611).

8617821 is a wasteful number, since it uses less digits than its factorization.

8617821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2872610.

The product of its digits is 5376, while the sum is 33.

The square root of 8617821 is about 2935.6125425539. The cubic root of 8617821 is about 205.0213818665.

The spelling of 8617821 in words is "eight million, six hundred seventeen thousand, eight hundred twenty-one".