21043344061 has 4 divisors (see below), whose sum is σ = 21074154912. Its totient is φ = 21012533212.

The previous prime is 21043344043. The next prime is 21043344079. The reversal of 21043344061 is 16044334012.

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 an interprime number because it is at equal distance from previous prime (21043344043) and next prime (21043344079).

It is a cyclic number.

It is not a de Polignac number, because 21043344061 - 2⁵ = 21043344029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043344001) 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, 15404401 + ... + 15405766.

It is an arithmetic number, because the mean of its divisors is an integer number (5268538728).

Almost surely, 2^21043344061 is an apocalyptic number.

It is an amenable number.

21043344061 is a deficient number, since it is larger than the sum of its proper divisors (30810851).

21043344061 is an equidigital number, since it uses as much as digits as its factorization.

21043344061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30810850.

The product of its (nonzero) digits is 6912, while the sum is 28.

Adding to 21043344061 its reverse (16044334012), we get a palindrome (37087678073).

The spelling of 21043344061 in words is "twenty-one billion, forty-three million, three hundred forty-four thousand, sixty-one".