21101120001 has 32 divisors (see below), whose sum is σ = 35645944320. Its totient is φ = 12221459712.

The previous prime is 21101119999. The next prime is 21101120011. The reversal of 21101120001 is 10002110112.

It is a happy number.

It is not a de Polignac number, because 21101120001 - 2¹ = 21101119999 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (21101120011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1762185 + ... + 1774118.

It is an arithmetic number, because the mean of its divisors is an integer number (1113935760).

Almost surely, 2^21101120001 is an apocalyptic number.

It is an amenable number.

21101120001 is a deficient number, since it is larger than the sum of its proper divisors (14544824319).

21101120001 is a wasteful number, since it uses less digits than its factorization.

21101120001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3536342 (or 3536336 counting only the distinct ones).

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

Adding to 21101120001 its reverse (10002110112), we get a palindrome (31103230113).

The spelling of 21101120001 in words is "twenty-one billion, one hundred one million, one hundred twenty thousand, one".