21011001201 has 6 divisors (see below), whose sum is σ = 30349223970. Its totient is φ = 14007334128.

The previous prime is 21011001197. The next prime is 21011001217. The reversal of 21011001201 is 10210011012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 11481336801 + 9529664400 = 107151^2 + 97620^2 .

It is not a de Polignac number, because 21011001201 - 2² = 21011001197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 2334555689 = 21011001201 / (2 + 1 + 0 + 1 + 1 + 0 + 0 + 1 + 2 + 0 + 1).

It is not an unprimeable number, because it can be changed into a prime (21011001251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1167277836 + ... + 1167277853.

It is an arithmetic number, because the mean of its divisors is an integer number (5058203995).

Almost surely, 2^21011001201 is an apocalyptic number.

It is an amenable number.

21011001201 is a deficient number, since it is larger than the sum of its proper divisors (9338222769).

21011001201 is a wasteful number, since it uses less digits than its factorization.

21011001201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2334555695 (or 2334555692 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21011001201 its reverse (10210011012), we get a palindrome (31221012213).

The spelling of 21011001201 in words is "twenty-one billion, eleven million, one thousand, two hundred one".