20668741 has 4 divisors (see below), whose sum is σ = 20873484. Its totient is φ = 20464000.

The previous prime is 20668733. The next prime is 20668759. The reversal of 20668741 is 14786602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9278116 + 11390625 = 3046^2 + 3375^2 .

It is a cyclic number.

It is not a de Polignac number, because 20668741 - 2³ = 20668733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20668697 and 20668706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20668721) 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, 102220 + ... + 102421.

It is an arithmetic number, because the mean of its divisors is an integer number (5218371).

Almost surely, 2^20668741 is an apocalyptic number.

It is an amenable number.

20668741 is a deficient number, since it is larger than the sum of its proper divisors (204743).

20668741 is a wasteful number, since it uses less digits than its factorization.

20668741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204742.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 20668741 is about 4546.2887061866. The cubic root of 20668741 is about 274.4340581460.

The spelling of 20668741 in words is "twenty million, six hundred sixty-eight thousand, seven hundred forty-one".