8147821 has 4 divisors (see below), whose sum is σ = 8888544. Its totient is φ = 7407100.

The previous prime is 8147813. The next prime is 8147833. The reversal of 8147821 is 1287418.

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 8147821 - 2³ = 8147813 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 (8147891) 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, 370345 + ... + 370366.

It is an arithmetic number, because the mean of its divisors is an integer number (2222136).

Almost surely, 2^8147821 is an apocalyptic number.

It is an amenable number.

8147821 is a deficient number, since it is larger than the sum of its proper divisors (740723).

8147821 is a wasteful number, since it uses less digits than its factorization.

8147821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740722.

The product of its digits is 3584, while the sum is 31.

The square root of 8147821 is about 2854.4388240073. The cubic root of 8147821 is about 201.2243314355.

The spelling of 8147821 in words is "eight million, one hundred forty-seven thousand, eight hundred twenty-one".