202102100021 has 8 divisors (see below), whose sum is σ = 213859419264. Its totient is φ = 190592303440.

The previous prime is 202102100009. The next prime is 202102100029. The reversal of 202102100021 is 120001201202.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 202102100021 - 2¹⁰ = 202102098997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202102099975 and 202102100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202102100029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61878986 + ... + 61882251.

It is an arithmetic number, because the mean of its divisors is an integer number (26732427408).

Almost surely, 2^202102100021 is an apocalyptic number.

It is an amenable number.

202102100021 is a deficient number, since it is larger than the sum of its proper divisors (11757319243).

202102100021 is a wasteful number, since it uses less digits than its factorization.

202102100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123761331.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 202102100021 its reverse (120001201202), we get a palindrome (322103301223).

The spelling of 202102100021 in words is "two hundred two billion, one hundred two million, one hundred thousand, twenty-one".