39521 has 2 divisors, whose sum is σ = 39522. Its totient is φ = 39520.

The previous prime is 39511. The next prime is 39541. The reversal of 39521 is 12593.

It is an a-pointer prime, because the next prime (39541) can be obtained adding 39521 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21025 + 18496 = 145^2 + 136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39521 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 39493 and 39502.

It is not a weakly prime, because it can be changed into another prime (39511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19760 + 19761.

It is an arithmetic number, because the mean of its divisors is an integer number (19761).

2³⁹⁵²¹ is an apocalyptic number.

It is an amenable number.

39521 is a deficient number, since it is larger than the sum of its proper divisors (1).

39521 is an equidigital number, since it uses as much as digits as its factorization.

39521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 270, while the sum is 20.

The square root of 39521 is about 198.7988933571. The cubic root of 39521 is about 34.0624572847.

The spelling of 39521 in words is "thirty-nine thousand, five hundred twenty-one".