21101011001 has 16 divisors (see below), whose sum is σ = 25194032640. Its totient is φ = 17289988800.

The previous prime is 21101010977. The next prime is 21101011033. The reversal of 21101011001 is 10011010112.

It is a happy number.

It is not a de Polignac number, because 21101011001 - 2³⁰ = 20027269177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21101011001.

It is not an unprimeable number, because it can be changed into a prime (21101011301) 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 15 ways as a sum of consecutive naturals, for example, 494081 + ... + 535086.

It is an arithmetic number, because the mean of its divisors is an integer number (1574627040).

Almost surely, 2^21101011001 is an apocalyptic number.

It is an amenable number.

21101011001 is a deficient number, since it is larger than the sum of its proper divisors (4093021639).

21101011001 is a wasteful number, since it uses less digits than its factorization.

21101011001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029304.

The product of its (nonzero) digits is 2, while the sum is 8.

Adding to 21101011001 its reverse (10011010112), we get a palindrome (31112021113).

The spelling of 21101011001 in words is "twenty-one billion, one hundred one million, eleven thousand, one".