20544521 has 2 divisors, whose sum is σ = 20544522. Its totient is φ = 20544520.

The previous prime is 20544487. The next prime is 20544523. The reversal of 20544521 is 12544502.

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., 16687225 + 3857296 = 4085^2 + 1964^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20544521 is a prime.

Together with 20544523, 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 (20544523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10272260 + 10272261.

It is an arithmetic number, because the mean of its divisors is an integer number (10272261).

Almost surely, 2^20544521 is an apocalyptic number.

It is an amenable number.

20544521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20544521 is an equidigital number, since it uses as much as digits as its factorization.

20544521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 20544521 is about 4532.6064245641. The cubic root of 20544521 is about 273.8831663079.

The spelling of 20544521 in words is "twenty million, five hundred forty-four thousand, five hundred twenty-one".