20561936 has 40 divisors (see below), whose sum is σ = 41842560. Its totient is φ = 9777024.

The previous prime is 20561927. The next prime is 20561999. The reversal of 20561936 is 63916502.

It is a happy number.

It is a super-3 number, since 3×20561936³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27455 + ... + 28193.

It is an arithmetic number, because the mean of its divisors is an integer number (1046064).

Almost surely, 2^20561936 is an apocalyptic number.

It is an amenable number.

20561936 is an abundant number, since it is smaller than the sum of its proper divisors (21280624).

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

20561936 is a wasteful number, since it uses less digits than its factorization.

20561936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831 (or 825 counting only the distinct ones).

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

The square root of 20561936 is about 4534.5270977247. The cubic root of 20561936 is about 273.9605320814.

The spelling of 20561936 in words is "twenty million, five hundred sixty-one thousand, nine hundred thirty-six".