21010221001 has 16 divisors (see below), whose sum is σ = 27735419520. Its totient is φ = 15408564480.

The previous prime is 21010220999. The next prime is 21010221053. The reversal of 21010221001 is 10012201012.

It is a cyclic number.

It is not a de Polignac number, because 21010221001 - 2¹ = 21010220999 is a prime.

It is a super-2 number, since 2×21010221001² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010231001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8023986 + ... + 8026603.

It is an arithmetic number, because the mean of its divisors is an integer number (1733463720).

Almost surely, 2^21010221001 is an apocalyptic number.

It is an amenable number.

21010221001 is a deficient number, since it is larger than the sum of its proper divisors (6725198519).

21010221001 is a wasteful number, since it uses less digits than its factorization.

21010221001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16050624.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21010221001 its reverse (10012201012), we get a palindrome (31022422013).

The spelling of 21010221001 in words is "twenty-one billion, ten million, two hundred twenty-one thousand, one".