1221301232021 has 12 divisors (see below), whose sum is σ = 1332127236132. Its totient is φ = 1119126093696.

The previous prime is 1221301231993. The next prime is 1221301232057. The reversal of 1221301232021 is 1202321031221.

It can be written as a sum of positive squares in 6 ways, for example, as 519704019025 + 701597212996 = 720905^2 + 837614^2 .

It is not a de Polignac number, because 1221301232021 - 2¹⁰ = 1221301230997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221301231984 and 1221301232002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221301232071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26351426 + ... + 26397731.

It is an arithmetic number, because the mean of its divisors is an integer number (111010603011).

Almost surely, 2^{1221301232021} is an apocalyptic number.

It is an amenable number.

1221301232021 is a deficient number, since it is larger than the sum of its proper divisors (110826004111).

1221301232021 is a wasteful number, since it uses less digits than its factorization.

1221301232021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52749320 (or 52749307 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 1221301232021 its reverse (1202321031221), we get a palindrome (2423622263242).

The spelling of 1221301232021 in words is "one trillion, two hundred twenty-one billion, three hundred one million, two hundred thirty-two thousand, twenty-one".