20209959 has 32 divisors (see below), whose sum is σ = 37332480. Its totient is φ = 10497600.

The previous prime is 20209951. The next prime is 20209961. The reversal of 20209959 is 95990202.

It is not a de Polignac number, because 20209959 - 2³ = 20209951 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20209951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2782 + ... + 6939.

It is an arithmetic number, because the mean of its divisors is an integer number (1166640).

Almost surely, 2^20209959 is an apocalyptic number.

20209959 is a deficient number, since it is larger than the sum of its proper divisors (17122521).

20209959 is a wasteful number, since it uses less digits than its factorization.

20209959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9748 (or 9742 counting only the distinct ones).

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

The square root of 20209959 is about 4495.5487985339. The cubic root of 20209959 is about 272.3883177276.

The spelling of 20209959 in words is "twenty million, two hundred nine thousand, nine hundred fifty-nine".