20909259 has 20 divisors (see below), whose sum is σ = 35697904. Its totient is φ = 11947824.

The previous prime is 20909209. The next prime is 20909281. The reversal of 20909259 is 95290902.

It is not a de Polignac number, because 20909259 - 2⁹ = 20908747 is a prime.

It is a super-2 number, since 2×20909259² = 874394223858162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20909209) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 17872 + ... + 19005.

Almost surely, 2^20909259 is an apocalyptic number.

20909259 is a deficient number, since it is larger than the sum of its proper divisors (14788645).

20909259 is an equidigital number, since it uses as much as digits as its factorization.

20909259 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36896 (or 36887 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 20909259 is about 4572.6643218150. The cubic root of 20909259 is about 275.4944668592.

The spelling of 20909259 in words is "twenty million, nine hundred nine thousand, two hundred fifty-nine".