1321231110021 has 24 divisors (see below), whose sum is σ = 1974709035000. Its totient is φ = 850251330432.

The previous prime is 1321231110007. The next prime is 1321231110029. The reversal of 1321231110021 is 1200111321231.

1321231110021 is a `hidden beast` number, since 1 + 321 + 2 + 311 + 10 + 0 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 40461322500 + 1280769787521 = 201150^2 + 1131711^2 .

It is not a de Polignac number, because 1321231110021 - 2⁷ = 1321231109893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1321231109976 and 1321231110003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321231110029) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 553095 + ... + 1717083.

It is an arithmetic number, because the mean of its divisors is an integer number (82279543125).

Almost surely, 2^{1321231110021} is an apocalyptic number.

It is an amenable number.

1321231110021 is a deficient number, since it is larger than the sum of its proper divisors (653477924979).

1321231110021 is a wasteful number, since it uses less digits than its factorization.

1321231110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1168373 (or 1168370 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 1321231110021 its reverse (1200111321231), we get a palindrome (2521342431252).

The spelling of 1321231110021 in words is "one trillion, three hundred twenty-one billion, two hundred thirty-one million, one hundred ten thousand, twenty-one".