21101010201 has 24 divisors (see below), whose sum is σ = 31311567560. Its totient is φ = 13683396096.

The previous prime is 21101010197. The next prime is 21101010209. The reversal of 21101010201 is 10201010112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 19383322176 + 1717688025 = 139224^2 + 41445^2 .

It is not a de Polignac number, because 21101010201 - 2² = 21101010197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101010209) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1736535 + ... + 1748643.

Almost surely, 2^21101010201 is an apocalyptic number.

It is an amenable number.

21101010201 is a deficient number, since it is larger than the sum of its proper divisors (10210557359).

21101010201 is a wasteful number, since it uses less digits than its factorization.

21101010201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17385 (or 17382 counting only the distinct ones).

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

Adding to 21101010201 its reverse (10201010112), we get a palindrome (31302020313).

The spelling of 21101010201 in words is "twenty-one billion, one hundred one million, ten thousand, two hundred one".