20805329 has 2 divisors, whose sum is σ = 20805330. Its totient is φ = 20805328.

The previous prime is 20805307. The next prime is 20805341. The reversal of 20805329 is 92350802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18318400 + 2486929 = 4280^2 + 1577^2 .

It is a cyclic number.

It is not a de Polignac number, because 20805329 - 2¹⁶ = 20739793 is a prime.

It is not a weakly prime, because it can be changed into another prime (20805529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10402664 + 10402665.

It is an arithmetic number, because the mean of its divisors is an integer number (10402665).

Almost surely, 2^20805329 is an apocalyptic number.

It is an amenable number.

20805329 is a deficient number, since it is larger than the sum of its proper divisors (1).

20805329 is an equidigital number, since it uses as much as digits as its factorization.

20805329 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 20805329 is about 4561.2858932542. The cubic root of 20805329 is about 275.0372577619.

The spelling of 20805329 in words is "twenty million, eight hundred five thousand, three hundred twenty-nine".