2100102021 has 36 divisors (see below), whose sum is σ = 3229692804. Its totient is φ = 1314739200.

The previous prime is 2100102013. The next prime is 2100102029. The reversal of 2100102021 is 1202010012.

It is an interprime number because it is at equal distance from previous prime (2100102013) and next prime (2100102029).

It can be written as a sum of positive squares in 6 ways, for example, as 171396 + 2099930625 = 414^2 + 45825^2 .

It is not a de Polignac number, because 2100102021 - 2³ = 2100102013 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 2100101994 and 2100102012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100102029) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1978831 + ... + 1979891.

It is an arithmetic number, because the mean of its divisors is an integer number (89713689).

Almost surely, 2^2100102021 is an apocalyptic number.

It is an amenable number.

2100102021 is a deficient number, since it is larger than the sum of its proper divisors (1129590783).

2100102021 is a wasteful number, since it uses less digits than its factorization.

2100102021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1862 (or 1842 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 2100102021 is about 45826.8700764082. The cubic root of 2100102021 is about 1280.5999021068.

Adding to 2100102021 its reverse (1202010012), we get a palindrome (3302112033).

The spelling of 2100102021 in words is "two billion, one hundred million, one hundred two thousand, twenty-one".