21212020111201 has 4 divisors (see below), whose sum is σ = 21422040112404. Its totient is φ = 21002000110000.

The previous prime is 21212020111127. The next prime is 21212020111253. The reversal of 21212020111201 is 10211102021212.

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 13595082496801 + 7616937614400 = 3687151^2 + 2759880^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212020111201 - 2³⁹ = 20662264297313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212020111291) 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, 105010000450 + ... + 105010000651.

It is an arithmetic number, because the mean of its divisors is an integer number (5355510028101).

Almost surely, 2^{21212020111201} is an apocalyptic number.

It is an amenable number.

21212020111201 is a deficient number, since it is larger than the sum of its proper divisors (210020001203).

21212020111201 is a wasteful number, since it uses less digits than its factorization.

21212020111201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210020001202.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21212020111201 its reverse (10211102021212), we get a palindrome (31423122132413).

The spelling of 21212020111201 in words is "twenty-one trillion, two hundred twelve billion, twenty million, one hundred eleven thousand, two hundred one".