210021211100021 has 4 divisors (see below), whose sum is σ = 210035315017344. Its totient is φ = 210007107182700.

The previous prime is 210021211099979. The next prime is 210021211100039. The reversal of 210021211100021 is 120001112120012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210021211100021 - 2⁶ = 210021211099957 is a prime.

It is a super-2 number, since 2×210021211100021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210021211099969 and 210021211100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210021211100621) 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, 7051936325 + ... + 7051966106.

It is an arithmetic number, because the mean of its divisors is an integer number (52508828754336).

Almost surely, 2^{210021211100021} is an apocalyptic number.

It is an amenable number.

210021211100021 is a deficient number, since it is larger than the sum of its proper divisors (14103917323).

210021211100021 is a wasteful number, since it uses less digits than its factorization.

210021211100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14103917322.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 210021211100021 its reverse (120001112120012), we get a palindrome (330022323220033).

The spelling of 210021211100021 in words is "two hundred ten trillion, twenty-one billion, two hundred eleven million, one hundred thousand, twenty-one".