6421523 has 2 divisors, whose sum is σ = 6421524. Its totient is φ = 6421522.

The previous prime is 6421511. The next prime is 6421559. The reversal of 6421523 is 3251246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6421523 - 2⁴ = 6421507 is a prime.

It is not a weakly prime, because it can be changed into another prime (6421573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3210761 + 3210762.

It is an arithmetic number, because the mean of its divisors is an integer number (3210762).

Almost surely, 2^6421523 is an apocalyptic number.

6421523 is a deficient number, since it is larger than the sum of its proper divisors (1).

6421523 is an equidigital number, since it uses as much as digits as its factorization.

6421523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 23.

The square root of 6421523 is about 2534.0724141192. The cubic root of 6421523 is about 185.8714473806.

Adding to 6421523 its reverse (3251246), we get a palindrome (9672769).

The spelling of 6421523 in words is "six million, four hundred twenty-one thousand, five hundred twenty-three".