2100001101021 has 24 divisors (see below), whose sum is σ = 3067568375040. Its totient is φ = 1384202229696.

The previous prime is 2100001101017. The next prime is 2100001101049. The reversal of 2100001101021 is 1201011000012.

It is a happy number.

It is not a de Polignac number, because 2100001101021 - 2² = 2100001101017 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 a junction number, because it is equal to n+sod(n) for n = 2100001100994 and 2100001101012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100001102021) 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, 20170926 + ... + 20274768.

It is an arithmetic number, because the mean of its divisors is an integer number (127815348960).

Almost surely, 2^{2100001101021} is an apocalyptic number.

It is an amenable number.

2100001101021 is a deficient number, since it is larger than the sum of its proper divisors (967567274019).

2100001101021 is a wasteful number, since it uses less digits than its factorization.

2100001101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129185 (or 129182 counting only the distinct ones).

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

Adding to 2100001101021 its reverse (1201011000012), we get a palindrome (3301012101033).

It can be divided in two parts, 2100001 and 101021, that added together give a palindrome (2201022).

The spelling of 2100001101021 in words is "two trillion, one hundred billion, one million, one hundred one thousand, twenty-one".