21001210221121 has 16 divisors (see below), whose sum is σ = 22665689964288. Its totient is φ = 19343776233600.

The previous prime is 21001210221107. The next prime is 21001210221157. The reversal of 21001210221121 is 12112201210012.

It is not a de Polignac number, because 21001210221121 - 2¹³ = 21001210212929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001210221095 and 21001210221104.

It is not an unprimeable number, because it can be changed into a prime (21001210221191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10150626 + ... + 12043156.

It is an arithmetic number, because the mean of its divisors is an integer number (1416605622768).

Almost surely, 2^{21001210221121} is an apocalyptic number.

It is an amenable number.

21001210221121 is a deficient number, since it is larger than the sum of its proper divisors (1664479743167).

21001210221121 is a wasteful number, since it uses less digits than its factorization.

21001210221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1894392.

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

Adding to 21001210221121 its reverse (12112201210012), we get a palindrome (33113411431133).

The spelling of 21001210221121 in words is "twenty-one trillion, one billion, two hundred ten million, two hundred twenty-one thousand, one hundred twenty-one".