20520389 has 2 divisors, whose sum is σ = 20520390. Its totient is φ = 20520388.

The previous prime is 20520337. The next prime is 20520403. The reversal of 20520389 is 98302502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11847364 + 8673025 = 3442^2 + 2945^2 .

It is a cyclic number.

It is not a de Polignac number, because 20520389 - 2¹⁶ = 20454853 is a prime.

It is a super-2 number, since 2×20520389² = 842172729422642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20520319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10260194 + 10260195.

It is an arithmetic number, because the mean of its divisors is an integer number (10260195).

Almost surely, 2^20520389 is an apocalyptic number.

It is an amenable number.

20520389 is a deficient number, since it is larger than the sum of its proper divisors (1).

20520389 is an equidigital number, since it uses as much as digits as its factorization.

20520389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 20520389 is about 4529.9435978829. The cubic root of 20520389 is about 273.7758881017.

The spelling of 20520389 in words is "twenty million, five hundred twenty thousand, three hundred eighty-nine".