2100001222021 has 4 divisors (see below), whose sum is σ = 2101446509932. Its totient is φ = 2098555934112.

The previous prime is 2100001222019. The next prime is 2100001222027. The reversal of 2100001222021 is 1202221000012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1469644619521 + 630356602500 = 1212289^2 + 793950^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100001222021 - 2¹ = 2100001222019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2100001221992 and 2100001222010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100001222027) 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, 722641776 + ... + 722644681.

It is an arithmetic number, because the mean of its divisors is an integer number (525361627483).

Almost surely, 2^{2100001222021} is an apocalyptic number.

It is an amenable number.

2100001222021 is a deficient number, since it is larger than the sum of its proper divisors (1445287911).

2100001222021 is a wasteful number, since it uses less digits than its factorization.

2100001222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1445287910.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 2100001222021 its reverse (1202221000012), we get a palindrome (3302222222033).

The spelling of 2100001222021 in words is "two trillion, one hundred billion, one million, two hundred twenty-two thousand, twenty-one".