20909268 has 18 divisors (see below), whose sum is σ = 52854074. Its totient is φ = 6969744.

The previous prime is 20909209. The next prime is 20909281. The reversal of 20909268 is 86290902.

It can be written as a sum of positive squares in only one way, i.e., 20903184 + 6084 = 4572^2 + 78^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 580813 = 20909268 / (2 + 0 + 9 + 0 + 9 + 2 + 6 + 8).

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 290371 + ... + 290442.

Almost surely, 2^20909268 is an apocalyptic number.

It is an amenable number.

20909268 is an abundant number, since it is smaller than the sum of its proper divisors (31944806).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20909268 is a wasteful number, since it uses less digits than its factorization.

20909268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580823 (or 580818 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 20909268 is about 4572.6653059239. The cubic root of 20909268 is about 275.4945063864.

The spelling of 20909268 in words is "twenty million, nine hundred nine thousand, two hundred sixty-eight".