102100120021 has 4 divisors (see below), whose sum is σ = 108106009452. Its totient is φ = 96094230592.

The previous prime is 102100119923. The next prime is 102100120043. The reversal of 102100120021 is 120021001201.

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 60937391025 + 41162728996 = 246855^2 + 202886^2 .

It is a cyclic number.

It is not a de Polignac number, because 102100120021 - 2⁷ = 102100119893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102100120061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3002944690 + ... + 3002944723.

It is an arithmetic number, because the mean of its divisors is an integer number (27026502363).

Almost surely, 2^102100120021 is an apocalyptic number.

It is an amenable number.

102100120021 is a deficient number, since it is larger than the sum of its proper divisors (6005889431).

102100120021 is an equidigital number, since it uses as much as digits as its factorization.

102100120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6005889430.

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

Adding to 102100120021 its reverse (120021001201), we get a palindrome (222121121222).

The spelling of 102100120021 in words is "one hundred two billion, one hundred million, one hundred twenty thousand, twenty-one".