20561308 has 12 divisors (see below), whose sum is σ = 37143232. Its totient is φ = 9948960.

The previous prime is 20561291. The next prime is 20561311. The reversal of 20561308 is 80316502.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82785 + ... + 83032.

Almost surely, 2^20561308 is an apocalyptic number.

It is an amenable number.

20561308 is a deficient number, since it is larger than the sum of its proper divisors (16581924).

20561308 is a wasteful number, since it uses less digits than its factorization.

20561308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165852 (or 165850 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20561308 is about 4534.4578507248. The cubic root of 20561308 is about 273.9577429639.

It can be divided in two parts, 2056 and 1308, that added together give a square (3364 = 58²).

The spelling of 20561308 in words is "twenty million, five hundred sixty-one thousand, three hundred eight".