1212202211021 has 4 divisors (see below), whose sum is σ = 1283508223452. Its totient is φ = 1140896198592.

The previous prime is 1212202211009. The next prime is 1212202211029. The reversal of 1212202211021 is 1201122022121.

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 469209930121 + 742992280900 = 684989^2 + 861970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212202211021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 71306012413 = 1212202211021 / (1 + 2 + 1 + 2 + 2 + 0 + 2 + 2 + 1 + 1 + 0 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212202211029) 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, 35653006190 + ... + 35653006223.

It is an arithmetic number, because the mean of its divisors is an integer number (320877055863).

Almost surely, 2^{1212202211021} is an apocalyptic number.

It is an amenable number.

1212202211021 is a deficient number, since it is larger than the sum of its proper divisors (71306012431).

1212202211021 is an equidigital number, since it uses as much as digits as its factorization.

1212202211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71306012430.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1212202211021 its reverse (1201122022121), we get a palindrome (2413324233142).

The spelling of 1212202211021 in words is "one trillion, two hundred twelve billion, two hundred two million, two hundred eleven thousand, twenty-one".