21012111011201 has 4 divisors (see below), whose sum is σ = 21013937686272. Its totient is φ = 21010284336132.

The previous prime is 21012111011197. The next prime is 21012111011231. The reversal of 21012111011201 is 10211011121012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21012111011201 - 2² = 21012111011197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21012111011231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 913320281 + ... + 913343286.

It is an arithmetic number, because the mean of its divisors is an integer number (5253484421568).

Almost surely, 2^{21012111011201} is an apocalyptic number.

It is an amenable number.

21012111011201 is a deficient number, since it is larger than the sum of its proper divisors (1826675071).

21012111011201 is a wasteful number, since it uses less digits than its factorization.

21012111011201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826675070.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21012111011201 its reverse (10211011121012), we get a palindrome (31223122132213).

The spelling of 21012111011201 in words is "twenty-one trillion, twelve billion, one hundred eleven million, eleven thousand, two hundred one".