102002100021 has 12 divisors (see below), whose sum is σ = 147386030220. Its totient is φ = 67978478400.

The previous prime is 102002100007. The next prime is 102002100029. The reversal of 102002100021 is 120001200201.

It can be written as a sum of positive squares in 2 ways, for example, as 20156900625 + 81845199396 = 141975^2 + 286086^2 .

It is not a de Polignac number, because 102002100021 - 2¹⁰ = 102002098997 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 = 102002099976 and 102002100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102002100029) 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 11 ways as a sum of consecutive naturals, for example, 1881930 + ... + 1935371.

It is an arithmetic number, because the mean of its divisors is an integer number (12282169185).

Almost surely, 2^102002100021 is an apocalyptic number.

It is an amenable number.

102002100021 is a deficient number, since it is larger than the sum of its proper divisors (45383930199).

102002100021 is a wasteful number, since it uses less digits than its factorization.

102002100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3820276 (or 3820273 counting only the distinct ones).

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

Adding to 102002100021 its reverse (120001200201), we get a palindrome (222003300222).

The spelling of 102002100021 in words is "one hundred two billion, two million, one hundred thousand, twenty-one".