102130100021 has 4 divisors (see below), whose sum is σ = 102130864044. Its totient is φ = 102129336000.

The previous prime is 102130100003. The next prime is 102130100029. The reversal of 102130100021 is 120001031201.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 38371324996 + 63758775025 = 195886^2 + 252505^2 .

It is a cyclic number.

It is not a de Polignac number, because 102130100021 - 2¹⁰ = 102130098997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 102130099975 and 102130100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102130100029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122930 + ... + 468371.

It is an arithmetic number, because the mean of its divisors is an integer number (25532716011).

Almost surely, 2^102130100021 is an apocalyptic number.

It is an amenable number.

102130100021 is a deficient number, since it is larger than the sum of its proper divisors (764023).

102130100021 is an equidigital number, since it uses as much as digits as its factorization.

102130100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764022.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 102130100021 its reverse (120001031201), we get a palindrome (222131131222).

The spelling of 102130100021 in words is "one hundred two billion, one hundred thirty million, one hundred thousand, twenty-one".