20505299 has 8 divisors (see below), whose sum is σ = 20814288. Its totient is φ = 20198880.

The previous prime is 20505269. The next prime is 20505307. The reversal of 20505299 is 99250502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20505299 - 2¹² = 20501203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20505209) 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 in 7 ways as a sum of consecutive naturals, for example, 20069 + ... + 21065.

It is an arithmetic number, because the mean of its divisors is an integer number (2601786).

Almost surely, 2^20505299 is an apocalyptic number.

20505299 is a deficient number, since it is larger than the sum of its proper divisors (308989).

20505299 is a wasteful number, since it uses less digits than its factorization.

20505299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1285.

The product of its (nonzero) digits is 8100, while the sum is 32.

The square root of 20505299 is about 4528.2777079150. The cubic root of 20505299 is about 273.7087631358.

The spelling of 20505299 in words is "twenty million, five hundred five thousand, two hundred ninety-nine".