1022121212221 has 4 divisors (see below), whose sum is σ = 1022466876732. Its totient is φ = 1021775547712.

The previous prime is 1022121212209. The next prime is 1022121212269. The reversal of 1022121212221 is 1222121212201.

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 509815992196 + 512305220025 = 714014^2 + 715755^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1022121212221 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 (1022121212201) 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, 172827820 + ... + 172833733.

It is an arithmetic number, because the mean of its divisors is an integer number (255616719183).

Almost surely, 2^{1022121212221} is an apocalyptic number.

It is an amenable number.

1022121212221 is a deficient number, since it is larger than the sum of its proper divisors (345664511).

1022121212221 is an equidigital number, since it uses as much as digits as its factorization.

1022121212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345664510.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1022121212221 its reverse (1222121212201), we get a palindrome (2244242424422).

The spelling of 1022121212221 in words is "one trillion, twenty-two billion, one hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".