1211021221021 has 8 divisors (see below), whose sum is σ = 1326473548920. Its totient is φ = 1100481758208.

The previous prime is 1211021220989. The next prime is 1211021221037. The reversal of 1211021221021 is 1201221201121.

It can be written as a sum of positive squares in 4 ways, for example, as 167383265625 + 1043637955396 = 409125^2 + 1021586^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1211021221021 - 2⁵ = 1211021220989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211021220986 and 1211021221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211021321021) 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, 1228215756 + ... + 1228216741.

It is an arithmetic number, because the mean of its divisors is an integer number (165809193615).

Almost surely, 2^{1211021221021} is an apocalyptic number.

It is an amenable number.

1211021221021 is a deficient number, since it is larger than the sum of its proper divisors (115452327899).

1211021221021 is a wasteful number, since it uses less digits than its factorization.

1211021221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2456432543.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1211021221021 its reverse (1201221201121), we get a palindrome (2412242422142).

The spelling of 1211021221021 in words is "one trillion, two hundred eleven billion, twenty-one million, two hundred twenty-one thousand, twenty-one".