21001010202121 has 16 divisors (see below), whose sum is σ = 21066099059200. Its totient is φ = 20936055261888.

The previous prime is 21001010202101. The next prime is 21001010202131. The reversal of 21001010202121 is 12120201010012.

It is a cyclic number.

It is not a de Polignac number, because 21001010202121 - 2¹³ = 21001010193929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001010202101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1010965891 + ... + 1010986663.

It is an arithmetic number, because the mean of its divisors is an integer number (1316631191200).

Almost surely, 2^{21001010202121} is an apocalyptic number.

It is an amenable number.

21001010202121 is a deficient number, since it is larger than the sum of its proper divisors (65088857079).

21001010202121 is a wasteful number, since it uses less digits than its factorization.

21001010202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23848.

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

Adding to 21001010202121 its reverse (12120201010012), we get a palindrome (33121211212133).

The spelling of 21001010202121 in words is "twenty-one trillion, one billion, ten million, two hundred two thousand, one hundred twenty-one".