20721683670041 has 4 divisors (see below), whose sum is σ = 21390125078784. Its totient is φ = 20053242261300.

The previous prime is 20721683670013. The next prime is 20721683670043. The reversal of 20721683670041 is 14007638612702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20721683670041 - 2¹⁸ = 20721683407897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20721683670043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 334220704325 + ... + 334220704386.

It is an arithmetic number, because the mean of its divisors is an integer number (5347531269696).

Almost surely, 2^{20721683670041} is an apocalyptic number.

It is an amenable number.

20721683670041 is a deficient number, since it is larger than the sum of its proper divisors (668441408743).

20721683670041 is an equidigital number, since it uses as much as digits as its factorization.

20721683670041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668441408742.

The product of its (nonzero) digits is 677376, while the sum is 47.

The spelling of 20721683670041 in words is "twenty trillion, seven hundred twenty-one billion, six hundred eighty-three million, six hundred seventy thousand, forty-one".