21002010011 has 4 divisors (see below), whose sum is σ = 21019704552. Its totient is φ = 20984315472.

The previous prime is 21002009957. The next prime is 21002010023. The reversal of 21002010011 is 11001020012.

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

It is a cyclic number.

It is not a de Polignac number, because 21002010011 - 2¹⁸ = 21001747867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002060011) 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, 8845490 + ... + 8847863.

It is an arithmetic number, because the mean of its divisors is an integer number (5254926138).

Almost surely, 2^21002010011 is an apocalyptic number.

21002010011 is a deficient number, since it is larger than the sum of its proper divisors (17694541).

21002010011 is a wasteful number, since it uses less digits than its factorization.

21002010011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17694540.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21002010011 its reverse (11001020012), we get a palindrome (32003030023).

The spelling of 21002010011 in words is "twenty-one billion, two million, ten thousand, eleven".