20661336 has 48 divisors (see below), whose sum is σ = 56738760. Its totient is φ = 6791040.

The previous prime is 20661323. The next prime is 20661367. The reversal of 20661336 is 63316602.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 3291 + ... + 7221.

Almost surely, 2^20661336 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20661336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28369380).

20661336 is an abundant number, since it is smaller than the sum of its proper divisors (36077424).

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

20661336 is a wasteful number, since it uses less digits than its factorization.

20661336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4016 (or 4009 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 20661336 is about 4545.4742326846. The cubic root of 20661336 is about 274.4012803562.

Adding to 20661336 its reverse (63316602), we get a palindrome (83977938).

The spelling of 20661336 in words is "twenty million, six hundred sixty-one thousand, three hundred thirty-six".