20661033 has 16 divisors (see below), whose sum is σ = 28290240. Its totient is φ = 13407744.

The previous prime is 20661023. The next prime is 20661041. The reversal of 20661033 is 33016602.

It is not a de Polignac number, because 20661033 - 2¹⁴ = 20644649 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20661013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19485 + ... + 20517.

It is an arithmetic number, because the mean of its divisors is an integer number (1768140).

Almost surely, 2^20661033 is an apocalyptic number.

It is an amenable number.

20661033 is a deficient number, since it is larger than the sum of its proper divisors (7629207).

20661033 is a wasteful number, since it uses less digits than its factorization.

20661033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 20661033 is about 4545.4409027068. The cubic root of 20661033 is about 274.3999389781.

Adding to 20661033 its reverse (33016602), we get a palindrome (53677635).

The spelling of 20661033 in words is "twenty million, six hundred sixty-one thousand, thirty-three".