2101102000021 has 4 divisors (see below), whose sum is σ = 2101207916844. Its totient is φ = 2100996083200.

The previous prime is 2101101999979. The next prime is 2101102000027. The reversal of 2101102000021 is 1200002011012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 103716202500 + 1997385797521 = 322050^2 + 1413289^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101102000021 - 2¹³ = 2101101991829 is a prime.

It is a super-2 number, since 2×2101102000021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2101101999971 and 2101102000007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101102000027) 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, 52928650 + ... + 52968331.

It is an arithmetic number, because the mean of its divisors is an integer number (525301979211).

Almost surely, 2^{2101102000021} is an apocalyptic number.

It is an amenable number.

2101102000021 is a deficient number, since it is larger than the sum of its proper divisors (105916823).

2101102000021 is a wasteful number, since it uses less digits than its factorization.

2101102000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105916822.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 2101102000021 its reverse (1200002011012), we get a palindrome (3301104011033).

The spelling of 2101102000021 in words is "two trillion, one hundred one billion, one hundred two million, twenty-one", and thus it is an aban number.