1321002021 has 8 divisors (see below), whose sum is σ = 1782557280. Its totient is φ = 870057392.

The previous prime is 1321002019. The next prime is 1321002043. The reversal of 1321002021 is 1202001231.

1321002021 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1321002021 - 2¹ = 1321002019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1321001988 and 1321002006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321002061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2652366 + ... + 2652863.

It is an arithmetic number, because the mean of its divisors is an integer number (222819660).

Almost surely, 2^1321002021 is an apocalyptic number.

It is an amenable number.

1321002021 is a deficient number, since it is larger than the sum of its proper divisors (461555259).

1321002021 is an equidigital number, since it uses as much as digits as its factorization.

1321002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5305315.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 1321002021 is about 36345.5914933297. The cubic root of 1321002021 is about 1097.2388105510.

Adding to 1321002021 its reverse (1202001231), we get a palindrome (2523003252).

The spelling of 1321002021 in words is "one billion, three hundred twenty-one million, two thousand, twenty-one".