21112100001 has 12 divisors (see below), whose sum is σ = 30507648912. Its totient is φ = 14069013336.

The previous prime is 21112099969. The next prime is 21112100017. The reversal of 21112100001 is 10000121112.

It is a happy number.

It is not a de Polignac number, because 21112100001 - 2⁵ = 21112099969 is a prime.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21112100101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 453231 + ... + 497636.

It is an arithmetic number, because the mean of its divisors is an integer number (2542304076).

Almost surely, 2^21112100001 is an apocalyptic number.

It is an amenable number.

21112100001 is a deficient number, since it is larger than the sum of its proper divisors (9395548911).

21112100001 is a wasteful number, since it uses less digits than its factorization.

21112100001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 953340 (or 953337 counting only the distinct ones).

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

Adding to 21112100001 its reverse (10000121112), we get a palindrome (31112221113).

It can be divided in two parts, 21112 and 100001, that multiplied together give a palindrome (2111221112).

The spelling of 21112100001 in words is "twenty-one billion, one hundred twelve million, one hundred thousand, one".