20665049 has 4 divisors (see below), whose sum is σ = 20674740. Its totient is φ = 20655360.

The previous prime is 20665039. The next prime is 20665067. The reversal of 20665049 is 94056602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 18215824 + 2449225 = 4268^2 + 1565^2 .

It is a cyclic number.

It is not a de Polignac number, because 20665049 - 2⁴ = 20665033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20665009) 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, 92 + ... + 6429.

It is an arithmetic number, because the mean of its divisors is an integer number (5168685).

Almost surely, 2^20665049 is an apocalyptic number.

It is an amenable number.

20665049 is a deficient number, since it is larger than the sum of its proper divisors (9691).

20665049 is an equidigital number, since it uses as much as digits as its factorization.

20665049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9690.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 20665049 is about 4545.8826425679. The cubic root of 20665049 is about 274.4177167075.

The spelling of 20665049 in words is "twenty million, six hundred sixty-five thousand, forty-nine".