100202120021 has 4 divisors (see below), whose sum is σ = 100203427500. Its totient is φ = 100200812544.

The previous prime is 100202120009. The next prime is 100202120033. The reversal of 100202120021 is 120021202001.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (100202120009) and next prime (100202120033).

It can be written as a sum of positive squares in 2 ways, for example, as 27393891121 + 72808228900 = 165511^2 + 269830^2 .

It is a cyclic number.

It is not a de Polignac number, because 100202120021 - 2⁶ = 100202119957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100202119984 and 100202120011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100202120071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 531116 + ... + 694613.

It is an arithmetic number, because the mean of its divisors is an integer number (25050856875).

Almost surely, 2^100202120021 is an apocalyptic number.

It is an amenable number.

100202120021 is a deficient number, since it is larger than the sum of its proper divisors (1307479).

100202120021 is an equidigital number, since it uses as much as digits as its factorization.

100202120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1307478.

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

Adding to 100202120021 its reverse (120021202001), we get a palindrome (220223322022).

The spelling of 100202120021 in words is "one hundred billion, two hundred two million, one hundred twenty thousand, twenty-one".