21001200122211 has 128 divisors (see below), whose sum is σ = 30618023328000. Its totient is φ = 12775624114176.

The previous prime is 21001200122171. The next prime is 21001200122257. The reversal of 21001200122211 is 11222100210012.

It is a de Polignac number, because none of the positive numbers 2^k-21001200122211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001200122281) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 5625821901 + ... + 5625825633.

It is an arithmetic number, because the mean of its divisors is an integer number (239203307250).

Almost surely, 2^{21001200122211} is an apocalyptic number.

21001200122211 is a deficient number, since it is larger than the sum of its proper divisors (9616823205789).

21001200122211 is a wasteful number, since it uses less digits than its factorization.

21001200122211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4233.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21001200122211 its reverse (11222100210012), we get a palindrome (32223300332223).

The spelling of 21001200122211 in words is "twenty-one trillion, one billion, two hundred million, one hundred twenty-two thousand, two hundred eleven".