20340521 has 2 divisors, whose sum is σ = 20340522. Its totient is φ = 20340520.

The previous prime is 20340497. The next prime is 20340539. The reversal of 20340521 is 12504302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19456921 + 883600 = 4411^2 + 940^2 .

It is a cyclic number.

It is not a de Polignac number, because 20340521 - 2⁶ = 20340457 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20340521.

It is not a weakly prime, because it can be changed into another prime (20370521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10170260 + 10170261.

It is an arithmetic number, because the mean of its divisors is an integer number (10170261).

Almost surely, 2^20340521 is an apocalyptic number.

It is an amenable number.

20340521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20340521 is an equidigital number, since it uses as much as digits as its factorization.

20340521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20340521 is about 4510.0466738161. The cubic root of 20340521 is about 272.9736274041.

Adding to 20340521 its reverse (12504302), we get a palindrome (32844823).

The spelling of 20340521 in words is "twenty million, three hundred forty thousand, five hundred twenty-one".