1021031312221 has 4 divisors (see below), whose sum is σ = 1021222772892. Its totient is φ = 1020839851552.

The previous prime is 1021031312219. The next prime is 1021031312263. The reversal of 1021031312221 is 1222131301201.

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 1009996860196 + 11034452025 = 1004986^2 + 105045^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021031312221 - 2¹ = 1021031312219 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 (1021031312201) 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, 95722336 + ... + 95733001.

It is an arithmetic number, because the mean of its divisors is an integer number (255305693223).

Almost surely, 2^{1021031312221} is an apocalyptic number.

It is an amenable number.

1021031312221 is a deficient number, since it is larger than the sum of its proper divisors (191460671).

1021031312221 is an equidigital number, since it uses as much as digits as its factorization.

1021031312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191460670.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 1021031312221 its reverse (1222131301201), we get a palindrome (2243162613422).

The spelling of 1021031312221 in words is "one trillion, twenty-one billion, thirty-one million, three hundred twelve thousand, two hundred twenty-one".