20305949 has 4 divisors (see below), whose sum is σ = 20507100. Its totient is φ = 20104800.

The previous prime is 20305931. The next prime is 20305951. The reversal of 20305949 is 94950302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16345849 + 3960100 = 4043^2 + 1990^2 .

It is a cyclic number.

It is not a de Polignac number, because 20305949 - 2⁸ = 20305693 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20305919) 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 3 ways as a sum of consecutive naturals, for example, 100424 + ... + 100625.

It is an arithmetic number, because the mean of its divisors is an integer number (5126775).

Almost surely, 2^20305949 is an apocalyptic number.

It is an amenable number.

20305949 is a deficient number, since it is larger than the sum of its proper divisors (201151).

20305949 is a wasteful number, since it uses less digits than its factorization.

20305949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201150.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 20305949 is about 4506.2122675258. The cubic root of 20305949 is about 272.8188854482.

The spelling of 20305949 in words is "twenty million, three hundred five thousand, nine hundred forty-nine".