20561266 has 8 divisors (see below), whose sum is σ = 33645744. Its totient is φ = 9346020.

The previous prime is 20561263. The next prime is 20561273. The reversal of 20561266 is 66216502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×20561266³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20561263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 467280 + ... + 467323.

It is an arithmetic number, because the mean of its divisors is an integer number (4205718).

Almost surely, 2^20561266 is an apocalyptic number.

20561266 is a deficient number, since it is larger than the sum of its proper divisors (13084478).

20561266 is a wasteful number, since it uses less digits than its factorization.

20561266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934616.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20561266 is about 4534.4532195183. The cubic root of 20561266 is about 273.9575564285.

Adding to 20561266 its reverse (66216502), we get a palindrome (86777768).

The spelling of 20561266 in words is "twenty million, five hundred sixty-one thousand, two hundred sixty-six".