21103212001 has 4 divisors (see below), whose sum is σ = 21181083904. Its totient is φ = 21025340100.

The previous prime is 21103211999. The next prime is 21103212007. The reversal of 21103212001 is 10021230112.

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 21103212001 - 2¹ = 21103211999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21103212007) 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, 38935545 + ... + 38936086.

It is an arithmetic number, because the mean of its divisors is an integer number (5295270976).

Almost surely, 2^21103212001 is an apocalyptic number.

It is an amenable number.

21103212001 is a deficient number, since it is larger than the sum of its proper divisors (77871903).

21103212001 is an equidigital number, since it uses as much as digits as its factorization.

21103212001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77871902.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21103212001 its reverse (10021230112), we get a palindrome (31124442113).

The spelling of 21103212001 in words is "twenty-one billion, one hundred three million, two hundred twelve thousand, one".