1210021111021 has 4 divisors (see below), whose sum is σ = 1281198823452. Its totient is φ = 1138843398592.

The previous prime is 1210021111003. The next prime is 1210021111063. The reversal of 1210021111021 is 1201111200121.

It is a happy number.

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 677310894121 + 532710216900 = 822989^2 + 729870^2 .

It is a cyclic number.

It is not a de Polignac number, because 1210021111021 - 2¹⁷ = 1210020979949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1210021110992 and 1210021111010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210021111001) 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, 35588856190 + ... + 35588856223.

It is an arithmetic number, because the mean of its divisors is an integer number (320299705863).

Almost surely, 2^{1210021111021} is an apocalyptic number.

It is an amenable number.

1210021111021 is a deficient number, since it is larger than the sum of its proper divisors (71177712431).

1210021111021 is an equidigital number, since it uses as much as digits as its factorization.

1210021111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71177712430.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1210021111021 its reverse (1201111200121), we get a palindrome (2411132311142).

The spelling of 1210021111021 in words is "one trillion, two hundred ten billion, twenty-one million, one hundred eleven thousand, twenty-one".