21011043641 has 8 divisors (see below), whose sum is σ = 24502675200. Its totient is φ = 18009465684.

The previous prime is 21011043617. The next prime is 21011043643. The reversal of 21011043641 is 14634011012.

It is not a de Polignac number, because 21011043641 - 2⁶ = 21011043577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21011043643) 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 7 ways as a sum of consecutive naturals, for example, 30628001 + ... + 30628686.

It is an arithmetic number, because the mean of its divisors is an integer number (3062834400).

Almost surely, 2^21011043641 is an apocalyptic number.

It is an amenable number.

21011043641 is a deficient number, since it is larger than the sum of its proper divisors (3491631559).

21011043641 is an frugal number, since it uses more digits than its factorization.

21011043641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61256708 (or 61256694 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

Adding to 21011043641 its reverse (14634011012), we get a palindrome (35645054653).

The spelling of 21011043641 in words is "twenty-one billion, eleven million, forty-three thousand, six hundred forty-one".