20807329 has 2 divisors, whose sum is σ = 20807330. Its totient is φ = 20807328.

The previous prime is 20807321. The next prime is 20807359. The reversal of 20807329 is 92370802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20493729 + 313600 = 4527^2 + 560^2 .

It is a cyclic number.

It is not a de Polignac number, because 20807329 - 2³ = 20807321 is a prime.

It is a super-2 number, since 2×20807329² = 865889880228482, which contains 22 as substring.

It is equal to p_1318558 and since 20807329 and 1318558 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20807329.

It is not a weakly prime, because it can be changed into another prime (20807321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10403664 + 10403665.

It is an arithmetic number, because the mean of its divisors is an integer number (10403665).

Almost surely, 2^20807329 is an apocalyptic number.

It is an amenable number.

20807329 is a deficient number, since it is larger than the sum of its proper divisors (1).

20807329 is an equidigital number, since it uses as much as digits as its factorization.

20807329 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20807329 is about 4561.5051244080. The cubic root of 20807329 is about 275.0460705183.

It can be divided in two parts, 2080 and 7329, that added together give a square (9409 = 97²).

The spelling of 20807329 in words is "twenty million, eight hundred seven thousand, three hundred twenty-nine".