21000211210121 has 16 divisors (see below), whose sum is σ = 24809406874560. Its totient is φ = 17524104813120.

The previous prime is 21000211210051. The next prime is 21000211210189. The reversal of 21000211210121 is 12101211200012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000211210121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000211210096 and 21000211210105.

It is not an unprimeable number, because it can be changed into a prime (21000211210021) 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, 410182850 + ... + 410234043.

It is an arithmetic number, because the mean of its divisors is an integer number (1550587929660).

Almost surely, 2^{21000211210121} is an apocalyptic number.

It is an amenable number.

21000211210121 is a deficient number, since it is larger than the sum of its proper divisors (3809195664439).

21000211210121 is a wasteful number, since it uses less digits than its factorization.

21000211210121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820417096.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21000211210121 its reverse (12101211200012), we get a palindrome (33101422410133).

The spelling of 21000211210121 in words is "twenty-one trillion, two hundred eleven million, two hundred ten thousand, one hundred twenty-one".