7644521 has 2 divisors, whose sum is σ = 7644522. Its totient is φ = 7644520.

The previous prime is 7644493. The next prime is 7644523. The reversal of 7644521 is 1254467.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5784025 + 1860496 = 2405^2 + 1364^2 .

It is an emirp because it is prime and its reverse (1254467) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7644521 - 2¹⁸ = 7382377 is a prime.

Together with 7644523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (7644523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3822260 + 3822261.

It is an arithmetic number, because the mean of its divisors is an integer number (3822261).

Almost surely, 2^7644521 is an apocalyptic number.

It is an amenable number.

7644521 is a deficient number, since it is larger than the sum of its proper divisors (1).

7644521 is an equidigital number, since it uses as much as digits as its factorization.

7644521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 29.

The square root of 7644521 is about 2764.8726914634. The cubic root of 7644521 is about 196.9926818380.

Adding to 7644521 its reverse (1254467), we get a palindrome (8898988).

The spelling of 7644521 in words is "seven million, six hundred forty-four thousand, five hundred twenty-one".