210121313021 has 4 divisors (see below), whose sum is σ = 210131916732. Its totient is φ = 210110709312.

The previous prime is 210121313011. The next prime is 210121313057. The reversal of 210121313021 is 120313121012.

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 71950015225 + 138171297796 = 268235^2 + 371714^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210121313021 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 (210121313011) 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, 5272076 + ... + 5311781.

It is an arithmetic number, because the mean of its divisors is an integer number (52532979183).

Almost surely, 2^210121313021 is an apocalyptic number.

It is an amenable number.

210121313021 is a deficient number, since it is larger than the sum of its proper divisors (10603711).

210121313021 is a wasteful number, since it uses less digits than its factorization.

210121313021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10603710.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 210121313021 its reverse (120313121012), we get a palindrome (330434434033).

The spelling of 210121313021 in words is "two hundred ten billion, one hundred twenty-one million, three hundred thirteen thousand, twenty-one".