8542821 has 24 divisors (see below), whose sum is σ = 13625920. Its totient is φ = 4663296.

The previous prime is 8542817. The next prime is 8542847. The reversal of 8542821 is 1282458.

It is not a de Polignac number, because 8542821 - 2² = 8542817 is a prime.

8542821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8542811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10725 + ... + 11493.

Almost surely, 2^8542821 is an apocalyptic number.

It is an amenable number.

8542821 is a deficient number, since it is larger than the sum of its proper divisors (5083099).

8542821 is a wasteful number, since it uses less digits than its factorization.

8542821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825 (or 802 counting only the distinct ones).

The product of its digits is 5120, while the sum is 30.

The square root of 8542821 is about 2922.8104625514. The cubic root of 8542821 is about 204.4248881757.

The spelling of 8542821 in words is "eight million, five hundred forty-two thousand, eight hundred twenty-one".