21001312001 has 4 divisors (see below), whose sum is σ = 21095488512. Its totient is φ = 20907135492.

The previous prime is 21001311977. The next prime is 21001312021. The reversal of 21001312001 is 10021310012.

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 21001312001 - 2³⁴ = 3821442817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001312021) 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, 47087921 + ... + 47088366.

It is an arithmetic number, because the mean of its divisors is an integer number (5273872128).

Almost surely, 2^21001312001 is an apocalyptic number.

It is an amenable number.

21001312001 is a deficient number, since it is larger than the sum of its proper divisors (94176511).

21001312001 is an equidigital number, since it uses as much as digits as its factorization.

21001312001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94176510.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21001312001 its reverse (10021310012), we get a palindrome (31022622013).

The spelling of 21001312001 in words is "twenty-one billion, one million, three hundred twelve thousand, one".