21240443001 has 16 divisors (see below), whose sum is σ = 29323713600. Its totient is φ = 13659619008.

The previous prime is 21240442961. The next prime is 21240443017. The reversal of 21240443001 is 10034404212.

It is not a de Polignac number, because 21240443001 - 2¹⁰ = 21240441977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21240443101) 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 15 ways as a sum of consecutive naturals, for example, 13591 + ... + 206556.

It is an arithmetic number, because the mean of its divisors is an integer number (1832732100).

Almost surely, 2^21240443001 is an apocalyptic number.

It is an amenable number.

21240443001 is a deficient number, since it is larger than the sum of its proper divisors (8083270599).

21240443001 is a wasteful number, since it uses less digits than its factorization.

21240443001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221288.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21240443001 its reverse (10034404212), we get a palindrome (31274847213).

The spelling of 21240443001 in words is "twenty-one billion, two hundred forty million, four hundred forty-three thousand, one".