20661266 has 8 divisors (see below), whose sum is σ = 31015884. Its totient is φ = 10322640.

The previous prime is 20661257. The next prime is 20661287. The reversal of 20661266 is 66216602.

It can be written as a sum of positive squares in 2 ways, for example, as 18619225 + 2042041 = 4315^2 + 1429^2 .

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

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, 56 + ... + 6428.

Almost surely, 2^20661266 is an apocalyptic number.

20661266 is a deficient number, since it is larger than the sum of its proper divisors (10354618).

20661266 is a wasteful number, since it uses less digits than its factorization.

20661266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7996.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20661266 is about 4545.4665327115. The cubic root of 20661266 is about 274.4009704681.

Adding to 20661266 its reverse (66216602), we get a palindrome (86877868).

The spelling of 20661266 in words is "twenty million, six hundred sixty-one thousand, two hundred sixty-six".