21043233641 has 32 divisors (see below), whose sum is σ = 23146572960. Its totient is φ = 19051315200.

The previous prime is 21043233637. The next prime is 21043233649. The reversal of 21043233641 is 14633234012.

It can be written as a sum of positive squares in 16 ways, for example, as 8233747600 + 12809486041 = 90740^2 + 113179^2 .

It is not a de Polignac number, because 21043233641 - 2² = 21043233637 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21043233649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27651701 + ... + 27652461.

It is an arithmetic number, because the mean of its divisors is an integer number (723330405).

Almost surely, 2^21043233641 is an apocalyptic number.

It is an amenable number.

21043233641 is a deficient number, since it is larger than the sum of its proper divisors (2103339319).

21043233641 is a wasteful number, since it uses less digits than its factorization.

21043233641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325.

The product of its (nonzero) digits is 10368, while the sum is 29.

Adding to 21043233641 its reverse (14633234012), we get a palindrome (35676467653).

The spelling of 21043233641 in words is "twenty-one billion, forty-three million, two hundred thirty-three thousand, six hundred forty-one".