21012111001201 has 4 divisors (see below), whose sum is σ = 21120982042852. Its totient is φ = 20903239959552.

The previous prime is 21012111001157. The next prime is 21012111001261. The reversal of 21012111001201 is 10210011121012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2002720280625 + 19009390720576 = 1415175^2 + 4359976^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012111001201 - 2⁹ = 21012111000689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012111001261) 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, 54435520536 + ... + 54435520921.

It is an arithmetic number, because the mean of its divisors is an integer number (5280245510713).

Almost surely, 2^{21012111001201} is an apocalyptic number.

It is an amenable number.

21012111001201 is a deficient number, since it is larger than the sum of its proper divisors (108871041651).

21012111001201 is a wasteful number, since it uses less digits than its factorization.

21012111001201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108871041650.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21012111001201 its reverse (10210011121012), we get a palindrome (31222122122213).

The spelling of 21012111001201 in words is "twenty-one trillion, twelve billion, one hundred eleven million, one thousand, two hundred one".