21012011121211 has 16 divisors (see below), whose sum is σ = 24162657292800. Its totient is φ = 18070944847200.

The previous prime is 21012011121193. The next prime is 21012011121293. The reversal of 21012011121211 is 11212111021012.

It is a cyclic number.

It is not a de Polignac number, because 21012011121211 - 2¹⁵ = 21012011088443 is a prime.

It is a super-2 number, since 2×21012011121211² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012011121011) 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, 70751635 + ... + 71047996.

It is an arithmetic number, because the mean of its divisors is an integer number (1510166080800).

Almost surely, 2^{21012011121211} is an apocalyptic number.

21012011121211 is a deficient number, since it is larger than the sum of its proper divisors (3150646171589).

21012011121211 is a wasteful number, since it uses less digits than its factorization.

21012011121211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141800370.

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

Adding to 21012011121211 its reverse (11212111021012), we get a palindrome (32224122142223).

The spelling of 21012011121211 in words is "twenty-one trillion, twelve billion, eleven million, one hundred twenty-one thousand, two hundred eleven".