21020101221001 has 4 divisors (see below), whose sum is σ = 21159307189504. Its totient is φ = 20880895252500.

The previous prime is 21020101220983. The next prime is 21020101221047. The reversal of 21020101221001 is 10012210102012.

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 21020101221001 - 2¹⁹ = 21020100696713 is a prime.

It is a super-2 number, since 2×21020101221001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020101221061) 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, 69602984025 + ... + 69602984326.

It is an arithmetic number, because the mean of its divisors is an integer number (5289826797376).

Almost surely, 2^{21020101221001} is an apocalyptic number.

It is an amenable number.

21020101221001 is a deficient number, since it is larger than the sum of its proper divisors (139205968503).

21020101221001 is a wasteful number, since it uses less digits than its factorization.

21020101221001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139205968502.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21020101221001 its reverse (10012210102012), we get a palindrome (31032311323013).

The spelling of 21020101221001 in words is "twenty-one trillion, twenty billion, one hundred one million, two hundred twenty-one thousand, one".