21001112002001 has 4 divisors (see below), whose sum is σ = 21678567227904. Its totient is φ = 20323656776100.

The previous prime is 21001112001983. The next prime is 21001112002019. The reversal of 21001112002001 is 10020021110012.

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 an interprime number because it is at equal distance from previous prime (21001112001983) and next prime (21001112002019).

It is a cyclic number.

It is not a de Polignac number, because 21001112002001 - 2⁶ = 21001112001937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001112002051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338727612905 + ... + 338727612966.

It is an arithmetic number, because the mean of its divisors is an integer number (5419641806976).

Almost surely, 2^{21001112002001} is an apocalyptic number.

It is an amenable number.

21001112002001 is a deficient number, since it is larger than the sum of its proper divisors (677455225903).

21001112002001 is an equidigital number, since it uses as much as digits as its factorization.

21001112002001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677455225902.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21001112002001 its reverse (10020021110012), we get a palindrome (31021133112013).

The spelling of 21001112002001 in words is "twenty-one trillion, one billion, one hundred twelve million, two thousand, one".