8542421 has 2 divisors, whose sum is σ = 8542422. Its totient is φ = 8542420.

The previous prime is 8542411. The next prime is 8542427. The reversal of 8542421 is 1242458.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6027025 + 2515396 = 2455^2 + 1586^2 .

It is a cyclic number.

It is not a de Polignac number, because 8542421 - 2⁶ = 8542357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p₅₇₃₈₁₂ and since 8542421 and 573812 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8542427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4271210 + 4271211.

It is an arithmetic number, because the mean of its divisors is an integer number (4271211).

Almost surely, 2^8542421 is an apocalyptic number.

It is an amenable number.

8542421 is a deficient number, since it is larger than the sum of its proper divisors (1).

8542421 is an equidigital number, since it uses as much as digits as its factorization.

8542421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2560, while the sum is 26.

The square root of 8542421 is about 2922.7420344601. The cubic root of 8542421 is about 204.4216975344.

Adding to 8542421 its reverse (1242458), we get a palindrome (9784879).

The spelling of 8542421 in words is "eight million, five hundred forty-two thousand, four hundred twenty-one".