21001010010001 has 4 divisors (see below), whose sum is σ = 24001154297152. Its totient is φ = 18000865722852.

The previous prime is 21001010009939. The next prime is 21001010010007. The reversal of 21001010010001 is 10001001010012.

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 21001010010001 - 2¹¹ = 21001010007953 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (7), and also a Moran number because the ratio is a prime number: 3000144287143 = 21001010010001 / (2 + 1 + 0 + 0 + 1 + 0 + 1 + 0 + 0 + 1 + 0 + 0 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001010010007) 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, 1500072143565 + ... + 1500072143578.

It is an arithmetic number, because the mean of its divisors is an integer number (6000288574288).

Almost surely, 2^{21001010010001} is an apocalyptic number.

It is an amenable number.

21001010010001 is a deficient number, since it is larger than the sum of its proper divisors (3000144287151).

21001010010001 is an equidigital number, since it uses as much as digits as its factorization.

21001010010001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3000144287150.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21001010010001 its reverse (10001001010012), we get a palindrome (31002011020013).

The spelling of 21001010010001 in words is "twenty-one trillion, one billion, ten million, ten thousand, one".