20640041 has 4 divisors (see below), whose sum is σ = 20665092. Its totient is φ = 20614992.

The previous prime is 20640019. The next prime is 20640047. The reversal of 20640041 is 14004602.

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 2755600 + 17884441 = 1660^2 + 4229^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20640041 is a prime.

It is a super-2 number, since 2×20640041² = 852022584963362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20640047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11246 + ... + 12951.

It is an arithmetic number, because the mean of its divisors is an integer number (5166273).

Almost surely, 2^20640041 is an apocalyptic number.

It is an amenable number.

20640041 is a deficient number, since it is larger than the sum of its proper divisors (25051).

20640041 is an equidigital number, since it uses as much as digits as its factorization.

20640041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25050.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 20640041 is about 4543.1311889489. The cubic root of 20640041 is about 274.3069756455.

Adding to 20640041 its reverse (14004602), we get a palindrome (34644643).

The spelling of 20640041 in words is "twenty million, six hundred forty thousand, forty-one".